Join Date: Jan 2005
Funny, informative, or just plain sad?
Talk About OLD SCHOOL!
Behold, you are about to take a trip back in time to see what we thought was state-of-the-art back 30 years ago. Some of this still hold up today, but some most certainly doesn't. 30 years from now we'll undoubtedbly look back and have a good laugh at what we thought was such hot stuff today.
I found this old thing in the form of a Q&A quiz, and I cleaned it up a lot to get it to fit.
Q&A 1. How do large inland aquariums obtain salt water for their fish?
With proper care a quantity of salt water may be used over and over and will last for many years. This is well attested by the Shedd Aquarium in Chicago, which in 1929 began to haul seawater from Key West, Florida, in railroad tank cars. About a million gallons were obtained in 160 tank-car loads by 1930, and this same water is in use today. The water is held in a reservoir in the basement of the aquarium building, and carefully filtered and aerated after being pumped through the fish exhibition tanks. Any water lost by evaporation may be replaced by fresh water, since the dissolved salts and minerals remain behind in greater concentration.
Q&A 2. Have dolphin fish ever been kept in captivity?
Because of their size and great activity, dolphin fish, Coryphaena hippurus, unless very small, usually do not survive for long if confined in a tank or small live car. However, in large pens maintained by the University of Hawaii as well as in the oceanarium at Marineland, Florida, dolphin fish have survived for many months at a time. In captivity they appear to spend almost their entire time at the surface of the water, swimming rapidly with a constant sculling motion of the tail. They showed a number of their characteristic color changes, particularly when excited at feeding time.
Q&A 3. What is the best treatment for fungus in fish tanks?
The best and most economical treatment for this condition appears to be Mercurochrome added in sufficient quantity to impart a reddish tinge to the water. Mercurochrome is harmless to fish, but will quickly destroy body and fin fungus in most cases, and the reddish color will eventually disappear from the water of its own accord. A more gradual and continuous preventative treatment is provided by soaking a small piece of chalk in Mercurochrome and placing this on the bottom of the tank. As the chalk slowly dissolves in the water the Mercurochrome is released at a fairly constant rate.
Q&A 4. Why do fish held in storage tanks often die when water is piped to them under pressure?
Fish kept in live bait or aquarium tanks will often die in a short time if the water piped to them has recently been under high pressure, as will happen if certain types of pumping apparatus is used. The reason for this is that an excess of air will often dissolve in the water under pressure, and after the pressure has been released small bubbles will form spontaneously, as when a carbonated drink is uncapped. Since fishes' bodies constantly absorb and give off water, bubbles may form in their body tissues, eventually killing them, as in the case of divers “bends”. Bulging eyes, or visible bubbles inside the fin membranes are a good indication that the water contains an excess of air. In severe cases the fish will float on the surface, unable to sink. This trouble can be avoided by piping the water overhead "settling tank" provided with baffles on which the bubbles can form. The water is then allowed to flow by gravity to the fish tank. Spraying the water into the tanks also helps eliminate bubble trouble.
Q&A 5. Will small starfishes live in a saltwater aquarium?
Yes, most small starfishes are quite hardy and will live in saltwater home aquaria. They make good scavengers in tanks containing fish, crabs, or other marine animals, as they constantly roam over the bottom and sides of the tank, picking up any particles of edible material. By themselves starfishes will live well in small bowls of sea water changed once weekly. They may be fed on small pieces of cut fish, shrimp, etc., care being taken not to put in more food than can be eaten quickly, since the excess will foul the water. Starfishes cannot live in fresh water or overly diluted seawater.
Q&A 6. Is it true that fish confined in a small bowl for years will continue to swim in circles for some time after being released?
Recent experiments involving fish that had been confined in small containers for periods of from 24 hours to several years have shown that there is no basis for this rather common supposition. In the majority of cases the fish swam directly away, apparently unaffected by their long "conditioning" by the confining walls of glass. A partial exception to this behavior was noted in the case of certain blind cave fish (Anoptichthus), which appear to learn the location of stones, plants, the walls of the aquarium, etc. by trial and error after colliding with them a number of times. A pair of these fish were several times enclosed in a glass cylinder placed in a larger tank. After the fish had learned to swim around the cylinder without coming in contact with the walls, they continued to circle for a time after the cylinder was removed, although in doing so they gradually migrated away from the space originally occupied by the cylinder.
Q&A 7. Will sharks and porpoises live together in captivity?
Although sharks and porpoises are traditionally considered to be enemies, porpoises will live quite amiably with certain kinds of sharks, as they have done for some time at the oceanarium at Marineland, Florida. The porpoises will occasionally seize the sharks’ tails with their teeth, but this is done in spirit of playfulness rather than aggressively. However, a large tiger shark (Galeocerdo cuvier) placed in with the porpoises on one occasion was eventually killed by them. The porpoises repeatedly rammed the shark in the region of the gills and elsewhere on the body with their blunt foreheads until the shark died from its injuries. Whether this normally happens in the sea, or whether it occurred because of the animals being confined to close quarters is difficult to say.
Q&A 8. Why is it beneficial to the fish to keep oysters in a small saltwater aquarium?
Since the oyster is a filter- feeder, it obtains its food by straining out small particles of organic material from the surrounding water. The amount of water filtered by an oyster in a day's time is most considerable, and if kept in a small aquarium an oyster will keep the water clear and quite free of suspended debris. In this way an oyster will substitute in a lesser way for a conventional charcoal filter, although an air pump must still be used to provide oxygen for the fish.
Q&A 9. What is a good source of live food for small aquarium fishes?
Perhaps the best universal food for both freshwater and saltwater tropicals is the brine shrimp, Artemia salina. These shrimp are world- wide in distribution but seldom seen except in pIaces where there is an abnormally high salt concentration. In these places brine shrimp are frequently to be found. In enormous numbers, such as in salt evaporating ponds and in Great Salt Lake in Utah. One of the most valuable discoveries in the field of tropical fish rearing was made when it was learned that if properly processed, the eggs of these shrimp may be dried and will keep for years, hatching in 24 hours when placed in a pan of sea water. The newly-hatched young make excellent food for small fishes, while the adults may be used to feed the larger ones. Brine shrimp may be reared to maturity in two weeks by placing them in arrested seawater to which a little additional salt is added and feeding them daily on a small quantity of fresh yeast or oatmeal.
Q&A 10. What is the cause of the blackening of the sand in saltwater aquarium tanks? Is there any remedy for this?
This blackening is caused by hydrogen sulfide, a poisonous gas which is formed by decaying organic material in the absence of air. Since salt water has less oxygen-retaining capacity than fresh water, food and waste products which become trapped in fine sand are often cut off from any source of aeration, and in this condition the normal bacteria which would eventually convert the wastes to harmless carbon dioxide and nitrates are unable to function. Instead anaerobic bacteria (those which thrive in the absence of air) convert the wastes to hydrogen sulfide gas and cause blackening of the sand, and frequently kill any fish in the tank. This hydrogen sulfide is the common cause of the “rotten egg: odor encounters over mud flats and mangrove swamps at low tide. In aquariums with fine sand in the bottom, blackening may become a serious problem, and aeration and circulation of the water may only partially solve this problem. The best preventative is to use sand with as coarse a grain as possible and to cover the bottom not more than 1/2 inch deep.
Q&A 11. Are there any aquarium fishes that can live in either fresh or salt water?
A few tropical aquarium fishes, such as certain top minnows (Fundulus, Cyprnodon) and the sailfin molly (Mollinesia) not only can tolerate water of any salinity from salt to fresh, but are able to breed under any of these conditions. Other top minnows and such fishes as glass minnows (Atherinidae), Scatophagus, glass perch, and freshwater blowfish can also tolerate various conditions of salinity, but they require water within a certain range to breed successfully.
Q&A 12. Should an aquarium be lighted from the sides or from above?
For the purposes of best visibility, an aquarium should be lighted from the top front, with the light directed backwards toward the middle of the tank. Additional lighting from the sides will improve the general appearance, if this is not too bright. It has been found experimentally that light from the sides alone has a bad physiological effect on the fish, and if the aquarium is lighted in this way, the fish will usually refuse to breed, lose appetite and vigor, and eventually die. Apparently the fish, used to light entering the water from above in nature, is unable to adjust itself to this artificial condition.
Q&A 13. What is the best treatment for tail rot (fungus) in fish tanks?
There are various chemicals that can be used for the treatment of fungus infection in fish tanks, the best of which, for the sake of economy, is mercurochrome. Mercurochrome added until the water is stained a deep pink is usually sufficient. The color is harmless to t he fish and will eventually disappear. In the case of fish held in tanks in which water is being added continuously, the water should be shut off for several hours (a day if possible) and aeration continued by means of an air compressor.
Q&A 14. Is the Marine Laboratory experimenting at present with aquarium fishes?
Yes. In view of the possibility of contributing to the operation of a modern aquarium in Miami in the near future, technicians are experimenting with live fish and other sea creatures in the newly constructed laboratory building at Virginia Key. The fish at present are thriving on a diet of frozen food which is easily prepared and will keep indefinitely under refrigeration until needed.
Q&A 15. For many years I have kept different types of fish at home in aquariums. One question has puzzled me all this time and I thought you might be able to help me. Do fish sleep?
New York City, New York
Yes, fish do sleep. Certain wrasses (Family Labridae) and parrot fish (Family Scaridae) are known to lie on their sides at the bottom of the tank. While in this position they remain motionless for long periods of time. One such fish even goes so far as to cover itself with a blanket of sand. It must be realized, of course, that fish have no eyelids, so that their eyes remain open while asleep. From a physiological viewpoint it is necessary that fish sleep. When an animal is awake its high activity causes the body cells to be broken down faster than they can be built up. During sleep the buildup of body tissues takes place. Thus in order to maintain life, animals must periodically go through a stage that we refer to as sleep.
Q&A 16. I am very much interested in securing some books regarding the care and feeding of saltwater fish and mammals in tanks. Will you please advise me where I may secure such books?
There are some books written on this subject but only a few are of any value. In setting up saltwater tanks there are many problems that must be taken care of before the animals can be placed in the tanks. These were discussed to some length in last week's Sea Secrets. The following is a short list of publications that may suit your needs. The Complete Aquarium Book by William T. Innes, published by the Halycon House, New York, New York (see chapter on Marine Aquaria). The New York Aquarium Guide by Charles Townsend, published by the New York Aquarium. The following three publications are free and may be obtained by writing to the Turtox Co., General Biological Supply House, Inc. 761-763 East 69th Place, Chicago 37, Illinois. Starting and Maintaining a Freshwater Aquarium, Service Leaflet #5. Aquarium Troubles; their prevention and remedy, Service Leaflet #48. Plants for the Balanced Aquarium, Service Leaflet #11.
Q&A 17. Recently I constructed a concrete tank of 2500 gallon capacity to keep salt water shrimp alive. The tank was water-proofed but its location made it impossible to have constantly changing salt water. Consequently, one quarter inch copper tubing was drilled with small holes, connected to an air compressor and placed in the bottom of the tank for aeration. One thousand shrimp were placed in the tank, and for 24 hours all of them appeared to be healthy, but during the next 24 hours every shrimp died. Why?
It is probable that the shrimp died because of the toxic reaction of the copper pipe. It is also possible that you did not allow proper soaking time of the tank in order to leach out the soluble material in the water-proof paint. It is suggested that the inside of the tank should be coated with a bitumen water mixed coating. Ordinary seawater taken from an unpolluted area should be quite suitable for your purpose. Shrimp may be held in water that is changed weekly, if they are not overcrowded. About three shrimp per cubic foot can be held with little aeration. A concentration of up to ten shrimp per cubic foot is possible with constant aeration such as you have. With the size of your tank, it is highly improbable that the shrimp died because of overcrowding. Your trouble appears to be caused by the poisonous materials. Those from the paint may disappear with plenty of soaking, but you should use some pipe other than copper for aeration.
Q&A 18. I have tried for many years to raise sea horses but have little or no success. One of the causes of death results from the formation of gas blisters on the animal. Can you give me some helpful hints on raising them?
The feeding of sea horses in itself is a relative simple thing. For the dwarf or pigmy sea horse (Hippocampus zosterae) brine shrimp suffice as their diet. Brine shrimp eggs can only be hatched in salt water. The best procedure is to add one-quarter teaspoonful of the eggs to a quart of sea water. The little shrimp will hatch in one to two days. If you do not have natural sea water, it is possible to make your own by adding one tablespoon of non-iodized salt to a quart of plain water. As the shrimp begin to hatch they may be added to the tank where the sea horses are kept. Additional shrimp could not be added until all of the first are eaten. In the feeding of the larger species (Hippocampus hudsonius punctulatus) the same procedure may be followed, with the necessary addition of a larger type of food, such as baby shrimp, and baby guppies and mollies. In all cases, the sea water in which the sea horses are kept should be clean and of constant salinity. This is done by marking the tank when natural sea water is placed in it, and as the water evaporates fresh water from the tap that has been allowed to stand for at least 24 hours to be added to the mark. In this manner the salinity will not ever be allowed to increase to a point where it would be harmful. As regards the blistersm the ones that from on the external surface of the animal may be removed by pricking it with a sharp and sterile needle. However, when these blisters are internal nothing can be done to save the sea horse. In case of doubt, to care and feeding of this or any other animal, a reputable pet shop should be consulted.
Q&A 19. I have a fifteen gallon aquarium in which I have tried to keep coral shrimp. To date I have been able to keep them about three weeks but I would like to be able to keep them longer. What special care, if any, should I give them to do this?
I presume the coral shrimp to which you refer are the banded white and red species, Stenopus hispidus. This species normally lives on the outer edges of the reef. Having such a habitat it would be particular susceptible to changes in salinity. Open seawater has a salinity of 34-36 parts per thousands. For the best results with your coral shrimp, running seawater of this salinity should be used. The Lerner Marine Laboratory of Bimini has successfully kept coral shrimp for several months by holding them in aquaria with running seawater.
Q&A 20. Do you have any information on building an aquarium at home?
While the length of an aquarium is not particularly important, of primary importance is the width in relation to the depth of water. As the great part of the oxygen essential to the fish will be absorbed by the water from the air in contact with the water surface, the "width" of the water should be equal to or greater than its depth. Incidentally, more pleasing effects in under-water gardening are possible in an aquarium of these proportions. After the desired size of the aquarium has been established, its finished weight must be considered, as this will largely determine the strength required of the materials used in the construction of the aquarium. The principal item of weight is that of the water, and this weight may be determined on this basis: One gallon of water weighs 8.337 pounds and contains 231 cubic inches. For example, if the aquarium is to be 30 inches long and 12 inches wide with a 10 inch depth, the volume of water will be 3,600 cubic inches or 15.5844 gallons of water, which will weigh 129.927 pounds. When sand and other ornaments are included, it will be necessary for the frame and glass to support approximately 1.80 pounds. The frame is the "backbone" of the aquarium and must therefore be perfectly squared and rigid. Wood should never be used for the frame since it does not provide sufficient rigidity and, if brought in contact with cement, it will tend to draw the oil from the cement, making it slightly porous so that moisture will ooze through the wood causing it to warp separating the wooden frame from the glass. Galvanized sheet-metal of 14 gauge, bent to form 1-inch angle-iron, may be used for an 18 gallon tank. Regular iron is generally used for tanks of more than 20 gallon capacity. Slate has been found to be the best material for the bottom. An 18 gallon tank (24 by 12 by 15 inches) may have a bottom of three-eights inch slate. If slate is not readily obtainable double-strength window glass or plate glass is strong enough for a small aquarium of 1 to 5 gallon capacity. Clear glass should be used for sides and ends. Regular double-strength window glass may be used for larger ones. Car windows obtained from junk dealers can be used, but new glass should be used, as old glass is usually scratched and this detracts from the appearance of the finished aquarium.
Q&A 21. Would you please tell me how I can keep live shrimp for bait?
Live marine shrimp may be kept successfully in two ways: either by keeping them in submerged slat pens in ocean water or by keeping them in tanks with circulating sea water. The first situation is possible only if there is access to salt or brackish water areas. The second method is in widespread use by many bait dealers in the coastal areas. Shrimp may be kept successfully for several weeks if certain precautions are followed. (1) The elimination of waste products appears to be an important consideration and efforts should be made to keep refuse and decaying material from the bottom of the tanks. (2) Circulation of water is important, especially if shrimp are crowded. A flow of one or two cubic feet per minute is recommended. (3) Crowding of shrimp should be guarded against. With no circulation, three shrimp per cubic foot of water is considered optimum density. If circulation of water is available, ten shrimp per cubic foot of water appears to be a safe maximum. These figures apply to shrimp which are to be kept several weeks, and therefore the number of shrimp per cubic foot could be increased for a short period of time. Several dozen shrimp per cubic foot of water can be kept for one or two days provided that there is sufficient circulation. (4) Air supply is not important as long as water circulation is good and if there is no overcrowding. (5) It is best not to allow the temperature to rise above 80 degrees Fahrenheit. (6) It is best to keep the holding tank in subdued light to reduce the growth of algae. (7) Feeding is not advised since uneaten fords tend to decay and contaminate the water. Shrimp survive well without food. (8) Sand in the bottom of the tanks permits the shrimp to bury themselves as is their custom, but it also acts as a trap for decayed material and soon develops a dark color and gives off odors. (9) In order to provide the shrimp with water of a constant salinity, it is advisable to pump from the deeper, cooler portions of the river or bays where the water is least affected by surface heating or rainfall. More details of the live shrimp industry of Florida can be obtained (free upon request) from Technical Bulletin #11 of the Marine Laboratory, University of Miami.
Q&A 22. Can seahorses be raised in a home aquarium?
Yes, seahorses can be raised successfully in home aquaria. Since the seahorse is a sluggish fish and therefore has a low metabolic rate, its oxygen consumption is low. Because of this, it is unnecessary to aerate the water if the surface area of the container is large enough to allow a sufficient exchange of oxygen between the air and the water. Food is the major problem in raising seahorses, which live on small crustaceans; that is members of the crab and shrimp family. One good food supply is brine shrimp, which can be purchased from almost any aquarium supply dealer. The eggs of these shrimp are first dried and then packaged for sale. These can be hatched by placing them in a bowl of water. After the shrimp hatch the adult is fed to the seahorses.
Q&A 23. I have a small salt water aquarium in which I am trying to keep sea horses, but so far they have all died. I fed them fried prepared aquarium food but this was left untouched. Is there anything I can buy that they will eat?
Sea horses and many other fishes will eat only live and actively swimming food. A favorite food is the brine shrimp, Artemia saliva. The eggs of this tiny creature can be bought in most aquarium supply stores at a small cost. The eggs, as needed, should be put in a small separate tank or jar until they have hatched and then the little shrimp may be siphoned off and fed to the fish. Avoid introducing the unhatched eggs in the tank as they will decompose and contaminate the water.
Q&A 24. How do you feed dwarf sea horses?
The dwarf seahorse feeds only on live, moving food. In nature it feeds on small crus tacea, i.e. copepods and amphipods that cling to plants. Swift moving open water copepods are too fast for it to capture. In the aquarium it readily eats newly hatched brine shrimp. Only gentle aeration should be used because strong aeration whirls the brine shrimp around too fast for the seahorses to capture them. Newly hatched brine shrimp live for at least two or three days with the seahorses. Thus feeding them every other day will keep live food constantly before them. Small brine shrimp should be kept with the seahorses at all times. Poorly fed adult dwarfs die in two or three weeks. Starvation for a day seriously runts young dwarfs and several days without food results in death. Brine shrimp eggs should not be placed in the seahorse tank because they tend to foul the water. Dead brine shrimp and seahorse droppings need to be siphoned off the bottom and the strained water returned to the aquarium or replaced with new seawater. The dwarf seahorse does not feed in dim light, so good illumination is a necessity. At Cedar Key on the northern Gulf coast of peninsular Florida, it does not breed when the period from sunrise to sunset is less than eleven hours - and it breeds best when the days are longer than twelve hours. This indicates the dwarf seahorse should be furnished at least twelve hours of light a day. Most writings on marine aquaria recommend dim light to avoid green water. Filtration also removes the brine shrimp and baby seahorses and consequently should be used only occasionally, unless a means of keeping the brine shrimp and baby seahorses from entering the filter is provided. A scum of blue green algae sometimes develops. It can be removed from the side of the tank with an aquarium scraper and from the algae used as a perch by rinsing it under the faucet.
Q&A 25. Can all fishes be kept alive in an aquarium?
If conditions in the aquarium can be made to resemble natural conditions sufficiently well, most fishes can be kept alive. The important factors influencing whether or not a fish will remain alive are: first, its condition on capture; second, after capture, the temperature and salinity of the water; and, third, the amount of food and oxygen available. Fishes in an aquarium can often become acclimatized to small and gradual changes in temperature and salinity, but sudden changes are usually harmful and should be avoided whenever possible. While some species of fish are hardy, others are very delicate and it is only with great care and risk that they can be captured and transferred to an aquarium in good condition. Fast swimming seagoing fishes such as mackerel are least able to withstand aquarium conditions. A common trouble is the ill effect of adding too much food, leading to decomposition. Parasites and disease may be due to contaminated equipment and are encouraged by a weakened resistance of the fish due to other factors.
Q&A 26. Suppose I caught a strange fish and wanted to bring it to some aquarium alive. How would I do it? What are the chances that the staff would buy it?
A livewell on the boat is the easiest way to keep fish alive, although tanks and even buckets will suffice for small fish if the water is changed from time to time to prevent depletion of oxygen. Some fish, for example: tuna, billfish, hammerhead sharks, cannot usually be kept alive in confinement. Others, such as tarpon and permit, do well. Most large aquariums have professional crews who catch fish for them, and they would not wish to purchase fish unless the fish in question is a rarity, such as ocean sunfish.
Q&A 27. How can I keep shrimp alive in a tank for more than a day?
There is no tried and true method available for keeping marine shrimp alive in a tank. The factors which can be controlled are temperature, salinity, clarity and purity of water, holding capacity of the tank, and tank cleanliness. Shrimp are tolerant of temperature changes so long as the temperature does not fall much below 60 degrees Fahrenheit or rise above 95 degrees Fahrenheit. If the tank is at least 50 gallons in capacity, the temperature will probably not fluctuate rapidly enough to harm the shrimp. With the aid of a hydrometer, salinities can be kept constant at between about 25-35 parts per thousand by the addition of salt water or fresh water as needed. If waste material and rotting bodies of dead shrimp are allowed to accumulate in the tank, they cause bacterial spoilage and subsequent loss of oxygen from the water. Dead shrimp can be removed by hand and a good filter is probably the best way to remove fine particles from the water. The filter should be large enough to handle a complete change of tank water every twelve hours. If the filter is adequate, the water will remain clear and pure. Since shrimp normally prefer to burrow in the bottom, the tank should be darkened. This will also keep down algal growth. The tank should be made of wood or aged concrete. For long periods of storage (up to a week) not more than four shrimp should be stocked per gallon of water. It is important not to feed more than the shrimp can eat quickly. Uneaten food should be removed from the tank after a short while.
Q&A 28. I am very interested in starting a saltwater home aquarium. Shall I use clean ocean water in it? Must I have filters?
For best results, "artificial" seawater should be used. The advantage of this over ocean water is that the artificial water is relatively free of bacteria and organic particles. Anything that traps uneaten food and creates spoilage is bad in a marine aquarium. For this reason, be sure to use a sub-sand filter of large size, a minimum of sand on the bottom, and few pieces of coral. Under no circumstances should the salt water be allowed to come in contact with metal. This means that filter, tank cover, and all pump features must be of glass or plastic.
Q&A 29. I would like to grow some sponges in an aquarium for a science project. Would this be possible? If it would, where can I obtain sponges? What kind of fishes should I put in with them?
Almost all sponges live in salt water and you would need a salt water aquarium in which to grow them. The commercial sponges grow only in warm seas and are not handled easily in small aquaria under artificial conditions.
Sponges feed on small particles of organic matter, plankton, or bacteria in the water. You could probably obtain small live sponges from one of the biological supply houses, addresses of which can be provided.
Q&A 30. Could you supply me with any information concerning keeping various species of shrimp, both fresh and salt water, alive and healthy in an aquarium?
There are two primary prerequisites for maintaining marine species of shrimp in aquaria. These are clean sand substrate, and a good system of water circulation. Penaeid shrimp (like the common commercialized bait shrimp of Florida and the Gulf of Mexico) can subsist on a diet of shredded fish or shrimp, although it is recommended that they not be fed when they are being held for a short time.
Q&A 31. Your interesting article on lobsters in the August, 1959, issue of Sea Frontiers has caused me to wonder whether there might be another crustacean with equally interesting habits and behavior but small enough to be kept in a small aquarium with small fish?
Unfortunately there are no dwarf species of lobster suitable for marine aquarium stocking. However, there is a group of lobster-like animals, the Spanish lobsters, which are not aggressive and might be suitable for aquaria. While most of the species are large, one, Scyllarus americanus, attains a total length of only two to three inches. As it has no claws it should not be able to harm other occupants of the tank. At the same time, it should be rather invulnerable to small fish as it has a heavy shell.
Q&A 32. I am having trouble making plants grow and keeping my aquarium clean. Can you offer me any advice that may aid?
Without seeing your aquarium set up it is rather difficult to advise you. However, one of the main troubles is overcrowding. This is much worse in marine aquaria than in fresh water. If you have no aeration the salt water aquarium is nearly impossible to balance. With good aeration only a few marine algae and a small number of animals should be used. The aquarium should get enough light, especially sunlight. A few good marine snails will assist in keeping the walls of the aquarium clean. An excellent new book on marine aquaria is The Salt Water Aquarium in the Home, by Robert L. Straughan, 1959, published by A. S. Barnes and Co., New York.
Q&A 33. For the past year, I have been successfully raising different types of marine fish in fresh water aquaria. Is there value to this in any other way than selling them as aquarium fishes?
Fish that live only in the sea cannot be raised in fresh water. The fishes you are raising probably are types of shore fishes which freely go back and forth into both fresh and salt water. Strictly speaking, these are not marine fishes. The raising and selling of aquarium fishes is a rather lucrative business, but one that must be entered cautiously. More often than not, the enterprise is unsuccessful and the investment is lost. Other than the sale of aquarium fishes, the rearing of such fishes is without value. On the other hand, much pleasure can be derived from the rearing and study of these interesting fishes. It is suggested that you stop at one of your local bookstores or libraries, and look at some of the recent literature that has been published on aquarium fishes. Also, a number of aquarium journals are published.
Q&A 34. Is there any paint for salt water fish that might also serve to keep fresh water live bait alive?
The wood or cement material of which the tank is made must first be thoroughly aged. This involves flushing with fresh water for a few days. New concrete tanks may leach for a week or more. Most hatcheries use asphalt for tank coating, either as paint or swabbed on while hot. This material has the advantage of being dark in color, thus tending to quiet the fish. Also, any good rubber-based paint should be suitable so long as it contains no copper.
Q&A 35. Could you give me some information about the operation of a small salt water aquarium?
There are three cardinal rules to follow in the care and maintenance of small salt water aquaria. The first is to keep it clean, free from excess food, coral, algae, et cetera. Marine aquaria are very apt to become polluted by food spoilage.
Rule No.2 is to stock sparingly, using no more than a single fish of one-inch length per gallon of water capacity. Thirdly, use quartz sand on a sub-sand filter in the bottom of the aquarium and good filtration. Many people make the mistake of putting too many decorative items in aquaria. Leave out coral, which soon becomes unsightly anyway, sponges and other marine plants. Be sure to watch the fish once they are in the tank, to guard against fin nipping. We recommend The Salt Water Aquarium in the Home by Straughan.
Q&A 36. We are interested in determining the feasibility of establishing a marine land in an inland area somewhat similar to those in the seashore areas of Florida and California. Would this be practical?
An inland marineland is possible but probably would be economically impractical. The two basic needs of these aquaria are a good supply of sea water and a good supply of specimens, and neither of these are readily available inland. Not all of the specimens in aquaria live very long and it is therefore necessary to collect new specimens regularly. Salt water in time will have to be replaced or the death rate may be very high. The John G. Shedd Aquarium, Grant Park, Chicago, maintains marine species. At one time it brought sea water to the aquarium from Key West, Florida, by railroad tank cars. It took 160 tank cars to fill the reservoirs. The small booklet the aquarium distributes for $1 per copy, "Guide to the John G. Shedd Aquarium," says that the sea water is expected to last for many years with the proper care. This aquarium also operated a railroad car which traveled in normal seasons about 20,000 miles to Maine, California and Florida to collect specimens. The costs of this non-profit aquarium are given in this booklet, together with descriptions of the aquarium and the collections.
Q&A 37. Could you send me some information about seahorses - what they eat, how I could get one in Michigan and how much it would cost?
You might have considerable trouble obtaining a live sea horse in Michigan. Would suggest you try some of the large pet stores in Detroit or other large cities near your home. They probably would cost from two to five dollars each in your area. These odd little fishes live fairly well on a diet of newly hatched brine shrimp, the eggs of which you can purchase in pet stores. Sea horses must have clean, warm sea water, or a substitute made from commercial grade "Neptune" salt, also available from the larger pet stores. Also, they need small, clean twigs on which to cling by the prehensile tails. There are lots of sea horses in Florida waters but it is difficult to ship them north. This is the reason why they are rare and expensive.
Q&A 38. I am trying to keep live shrimp for bait. Would you please send me information on their care and feeding? I have experienced some difficulty with the shrimp eating each other.
One of the most serious problems encountered in keeping shrimp involves waste material and the rotting bodies of dead shrimp. If allowed to accumulate this waste causes bacterial growth, the production of toxic metabolic compounds and subsequent loss of oxygen. A good filter of spun glass and charcoal large enough to handle a complete change of tank water each twelve hours is the best way to remove fine material from the water. Dead shrimp can be removed by hand. Shrimp are tolerant of temperature changes as long as the temperature does not fall much below 60 degrees Fahrenheit or go above 95 degrees Fahrenheit. If the tank is the 50-100 gallon size the temperature probably will not fluctuate rapidly enough to harm the bait. Salt content can be kept constant - about that of the water from which the shrimp were taken - by adding salt water or fresh, using a hydrometer calibrated to measure salinity. The tank should be constructed of wood or aged concrete and be kept covered to insure darkness. Shrimp are naturally cannibalistic. For extended periods of storage - a week or longer - no more than four shrimp should be stocked to a gallon. Liver is a good diet, but care must be exercised in feeding no more than the shrimp can eat and removing uneaten food each day.
Q&A 39. I want to breed adult mullet, hatch their eggs and rear the young in an aquarium for a science fair. Can you give me advice on starting such a project?
Adult mullet are often difficult to keep in aquaria. Furthermore, in nature mullet spawn in deep water, miles off the coastline, so you probably would have a very difficult time trying to obtain and hatch mullet eggs. It is suggested you work with one of three other fish instead: the sergeant major (Abudefduf saxatilis), commonly found among pilings at the seashore; sunfishes, which build nests and are found in fresh-water canals and lakes; or Zebra danio, which can be obtained in any aquarium or pet store. With the latter be certain to ask for ripe fish. Anyone of these species would make an interesting study. A good reference for this type of project is tropical Aquarium Fish by William Innes. This publication should be available at a nearby public or college library.
Q&A 40. Although I change their water daily, the small turtles I am keeping in a large plastic container are covered with algae. Is the algae harmful to the turtles? Should I remove it?
The algae on your turtles is not harmful. There is no necessity for its removal.
Q&A 41. Whenever I visit a large oceanarium I am amazed that the large sharks and other predatory fish and mammals do not seem to eat the small fry swimming about in the tank with them. Is it because the tank occupants are well-fed and do not become hungry enough to attack one another?
You are probably right, but no one knows how many of the small fishes are eaten at night, because no one is there to watch them. Aquarium studies have also shown that sharks fed a regular aquarium diet in captivity, soon cease the continuous forays of feeding they are thought to carry out in nature. In addition, for some unknown reason certain sharks seem to cut down on the amount of food they eat in the aquarium, and may even require force feeding. Frequently they may die of starvation.
Q&A 42. I have a fantastic crab in my aquarium which has marine seaweed growing all over its arms and body. It looks exactly like a clump of waving seaweed. Does this crab deliberately plant and cultivate the seaweed on itself?
It is almost impossible to say whether this seaweed was deliberately placed or grew fortuitously, without definite establishment of the species. Some small crabs are habitually covered with algae and sponges which become attached to their carapace. In the case of spider crabs, these algae are deliberately attached to small hooks on the back of the crab and the kinds of growth may be changed according to the habitat in which the animal is found. Both methods are, of course, for camouflage.
Q&A 43. I am interested in starting a marine life exhibit which can be transported by trailer trucks. I would like to know what problems would be involved in the way of a proper sea water solution, far from the sea, and what foods sea animals such as whales, sharks, porpoises, dolphins, rays and octopuses require, or can they exist on a diet of raw meat?
Perhaps you would do well to contact such organizations as the Seaquarium at Miami for information relative to such an exhibit. It is difficult to keep sharks in aquaria because of the sensitivity of these animals to copper salts and other chemicals commonly used to keep down the growth of algae. Also, even such large aquaria as the Seaquarium are unable to keep, even on a short-term basis, such oceanic types as hammerheads, makos, and the like. Whales are difficult to capture and it is hard to visualize a portable exhibit for them. Octopuses will live and do fairly well on a diet of crabs. The preparation of a transportable exhibit to feature such large oceanic animals as those you list, poses problems very difficult in nature and which we cannot answer at this time. Most exhibits feature small freshwater and marine tropical species, and even these small animals are continually being replaced. You might also consult the John G. Shedd Aquarium in Chicago, for they have been successful in maintaining many tropical marine species in that city.
Q&A 44. How do public aquaria, if any, manage to keep deep-sea species of fish in an aquarium, considering that these fish live under great pressure and in total darkness in their native habitat? Perhaps infrared light would get around the latter problem but what about the pressure?
Public aquaria and other establishments do not keep deep-sea species, for the problems involved are very great. Unless the fish has a swim, or air bladder, it is unlikely that the fish would be disturbed by changes in pressure. Evidence (according to deep-sea biologists that I have talked to) indicates that deep-sea fish die of “heat prostration” -- not from a decrease in pressure. Hence, it would seem that temperature of the aquariums would be extremely important; if one could bring the fish up from great depths, maintaining the low temperature existing at great depth. The aquariums would thus not have to be pressurized, as implied.
Q&A 45. On a recent trip to the Florida Keys, I picked up some interesting pieces of coral which were placed in our small aquarium upon returning home. As soon as the coral was placed in the tank, our assortment of freshwater fish seemed to have difficulty in breathing and continually came to the surface to gulp air. As soon as the coral was removed, things seemed to return to normal. Can you explain this and give me some advice?
Your problems are almost certainly due to the decomposition of animal matter on or within the coral pieces, and had the coral remained in the tank it probably would have killed all the fish. Even had the coral been alive when placed in the tank, the coral animals (polyps) at the surface of the coral would have quickly died, for they are physiologically adapted only to salt water. After dying they would have begun to decompose rapidly. Additionally, hosts of other organisms such as algae, sponges, tiny crustaceans, and worms, usually present in coral, also would have died and begun to decompose. The same would be true of dried coral for the contact with water would have started decomposition in this as well. Coral specimens that have been soaked in Clorox until they are white are usually devoid of animal matter, and can be placed in aquaria after soaking out all traces of the Clorox with fresh water until all odor of Clorox or decaying animal matter are gone. Sometimes there are stains on the surface of the coral, but these do not affect the usability of the specimen. Aquarist supply houses often sell pieces of coral for home aquaria, which have been bleached and weather-soaked for several months.
Q&A 46. Is it possible to keep mollusks alive for a long period of time in a ten-gallon aquarium? Also, could some species of Cypraea be kept alive in an aquarium?
It is possible to keep certain kinds of mollusks in a small aquarium if you follow some general rules: (1) do not put too many specimens in the tank; (2) select specimens that live in bays and enclosed water rather than those from the open ocean shore; (3) select specimens that live on rocky bottom areas rather than sand which easily becomes foul without adequate circulation in the tank; (4) place a few rocks having healthy algae in the tank for herbivorous snails; replace the rocks when the algae is all eaten or if it dies; (5) if you keep carnivorous snails, remove excess food before it decomposes. Specimens of Cypraea will not do well in a small tank unless you supply clean, highly oxygenated seawater in large quantities. The tritons (Cymatium), murexes (Murex), purpuras (Thais), nerites (Neritina and Nerita), periwinkles (Littorina) and cerites (Cerithium) are examples of snails that could live in a small tank. Some bivalves, such as the scallops (Pecten) and several kinds of oysters and mussels can be kept without sand. The water in your tank should have salinity and temperature characteristics as close to the animals' normal environment as possible.
Q&A 47. My biology group is planning to collect marine samples for an aquarium. Can you give us information that might be helpful in collecting, preserving, and transporting live specimens?
Although many specimens of marine life can be collected along the shore with a dipnet, a more comprehensive collection can be obtained from shore waters by diving. A short-handled, fiberglass-screen hand net and gloves to protect against stinging organisms would be useful in this. Other methods such as seining or poisoning could be used with even greater effect, but usually require a permit from the state involved. Fishes should be preserved immediately in 10 percent freshwater formalin (not seawater formalin). After a week in this solution, the specimens can be soaked in water to remove the formalin and then placed in 40 percent isopropanol (or 70 percent ethanol). Invertebrates should be killed or deeply anaesthetized by placing them in fresh water for at least several hours; otherwise, crabs may throw off their legs and brittlestars break up. Invertebrates and algae can be put directly into 70 percent ethanol after collection. The preserved specimens can be transported in five-gallon or smaller glass jars. Place in each jar, on good rag paper with India ink (or pencil), a label noting the collection location, date collected and collector(s). Live specimens can be collected by hand or caught in the hand net if they are mobile. They must be transported in plastic containers, since metal containers will poison the water. The large plastic bags used in shipping tropical fish can be obtained at a pet shop. Pour only enough water in the plastic bag to cover the specimens and tie the bag closed, leaving a large air space inside. Seawater can also be transported in the bags; however, no specimens should be put in this water until it is placed in the aquarium.
Q&A 48. We have tried unsuccessfully to keep Nomeus, the Portuguese man-of-war fish, alive in a 52-gallon aquarium. Can this fish be kept alive in captivity? Also, is it possible to catch small flyingfishes at night using nets, and are they aquarium fish?
The man-of-war fish, Nomeus gronowi, can be kept alive in running seawater aquaria for as long as a few weeks but in recirculating aquaria they generally live no longer than a few days. The biggest problem seems to be that Nomeus will not accept food in an aquarium. It is possible to dipnet flyingfishes at night with the aid of a light hung above or just under the surface. Flyingfishes do not survive well in aquaria.
Q&A 49.Could you give me information on setting up and maintaining a saltwater aquarium? Can the fishes and crabs we catch in local bays be kept alive?
Many of the fishes and invertebrates taken from bays and estuaries can be kept in aquaria without great difficulty. They must not be crowded, however, and some species must have cover in the form of rocks or shells. Aquaria smaller than ten gallons are not practical for most marine fishes, although pipefishes, sea horses, and other fairly sedentary species have been kept successfully in smaller containers. A good aeration and filtration system are important. An article on this subject appeared in the Christmas, 1963, Sea Frontiers (Volume 9, Number 5). For fuller treatment, see Robert P. L. Straughan's book, The Salt-Water Aquarium in the Home, available through the Foundation's Book Department. The price is $8.50, less a 10 percent discount to Members. For a more technical treatment, see Sea Water Systems for Experimental Aquariums, a recent Government publication. It consists of a collection of papers assembled and edited by John R. Clark and Roberta Clark of the Sandy Hook Marine Laboratory. The 192-page publication will be particularly interesting to marine biologists and the more serious aquarists. It is available as Bureau of Sport Fisheries and Wildlife Report 23, from the Superintendent of Documents, Government Printing Office, Washington, D. C. 20402. The price is $1.25 per copy.
Q&A 50. At our school, we have a tank used for marine life. The container is 8 feet long, 4 feet wide, and 4 feet deep. Some of our sea urchins and clams have died. The temperature and salinity appear to be right and we assume that the animals are not getting enough food. What would you recommend to enrich the water?
We doubt if your aquarium water lacks nutrients. Very slight changes in acidity, dissolved organic material, metallic ion content, etc., can kill the animals. If you are not using a sub-surface filter and bubbling plenty of air through the water, you may continue to have trouble. We recommend cleaning the aquarium completely, installing a good filtering and aerating system and then adding animals, a few at a time, until you learn what you can keep and what you cannot.
Q&A 51. In my saltwater aquarium, I frequently notice a fish rubbing or scratching its sides against the coral or the sand. Is this behavior normal?
Cheek scratching and side scratching is normal behavior in fishes. An excessive display of this type, however, may be an indication of external parasites.
Q&A 52. As a member of the St. Petersburg Shell Club, I intend to exhibit a collection of sea anemones at a coming show. One of my anemones - a deep orange animal - recently caused problems for me. The center of the anemone became like a white balloon while the color of its tentacles turned to a much lighter shade. While this was happening the water turned milky. Although I have changed the water several times, this continues to happen. Can you tell me how to solve this problem?
It is impossible to say what caused the water containing your orange sea anemone to turn milky. However, one of the commonest difficulties is an insufficient volume of water for the size of the animal kept in it. One or two large anemones might require at least a 15-gallon aquarium with aeration and filtration. In a smaller tank, uneaten food materials and waste products soon foul the water. The secret of keeping marine animals healthy is to keep very few in the greatest possible volume of water, and to circulate and filter the water with an aquarium air pump.
Q&A 53. We are having problems keeping our saltwater aquarium fishes alive. Do you have any information on the dietary requirements of various types of marine life that are suitable for aquariums?
The Jan.-Feb. issue of Salt Water Aquarium, a bi-monthly magazine published for marine aquarium enthusiasts, is devoted to the problems of feeding saltwater aquarium animals. The magazine (50 cents per copy) can be obtained from its publishers, Coral Reef Exhibits, P.O. Box 59-2214, Miami, Florida 33159.
Q&A 54. We have two 29 gallon saltwater tanks in our beach house which we keep stocked with local fish during the summer. Although the tanks are kept clean and well-aerated, some fish just will not live more than a few hours in them. Invariably it is the rarer fishes which die first, and I suspect they are more sensitive to temperature changes than the killies. I am thinking about installing a cooling and settling reservoir tank which would be sunk in the sand beneath the house, and which would supply the aquaria via a recirculating pump. May I have some opinion on this suggestion?
During the hot summer months it is almost impossible to keep temperate water fishes in an aquarium unless some system is used to cool the water. The scheme you suggest will probably work, although you might also obtain an old refrigerator and circulate your water through plastic coiled tubing at about 68-70 degrees.
Q&A 55. My Murex lays eggs about every six weeks. Can you tell me if this snail is hermaphroditic, and if so, what the conditions might be for hatching? Also, what would be the incubation time?
Without knowing what species Murex you have in your aquarium, it is very difficult to give you any information other than generalities. There is no Murex known that is hermaphroditic, but females often produce infertile eggs in the absence of a male. There is always a possibility, however, that the female stored the sperm of a male in her body before capture. This does occur in some marine snails. If this were the case, the animal could lay successive, fertile, egg masses over a period of time. The physical conditions and incubation time vary greatly from species to species. If your snail eggs are fertile, it is still possible that the young of your Murex would hatch out as free-swimming larvae, in which case it would be an extremely difficult and complicated task to keep them alive, even in a well-equipped laboratory. If yours is a species whose young undergo larval development within the egg capsule, there would be a better chance for survival under the conditions that were suitable for the adult.
Q&A 56. I have heard that ultraviolet light may be used as a parasite killer on small marine fish. Parasites have been a problem in saltwater aquariums, and I was interested in any information available on the subject.
Ultraviolet light is used by fish culturists, but only to sterilize the water entering the aquarium. Used in this way the light eliminates bacteria and fungi, and possibly the eggs and larvae of any parasites that happen to be in the entering flow. Any attempt, however, to apply ultraviolet light directly to fish infected with ectoparasites would probably injure the fish as much as the parasites.
Q&A 57. I am interested in keeping fishes and porpoises in tanks or ponds for display purposes. I have heard that tarpon, snook, sheepshead, mullet, and some other fishes can live in low salinity. Do you think that they would survive in well water?
Keeping fishes for display requires a sizeable investment in both time and money. The first step is to test the well water to determine if it is suitable for the types of fishes you wish to keep. Well water is sometimes devoid of oxygen and heavily charged with iron and hydrogen sulphide. This is almost certainly true in your area where shallow wells are often producers of water of poor quality. Hydrogen sulphide is generally indicated by a rotten egg odor. The water may also be coffee-colored from organic acids. These conditions are lethal to fishes, but the following method should help to overcome the problems. Pump the water into a raised pond of about 1/4 acre (about 110 feet on a side and 5 to 6 feet deep), so that the wind can aerate the water and remove odors. After standing about a week, this water can then be pumped into the fish tank. You should pump only the surface 20% of the supply pond each day and refill it immediately for the next day's use. You may also find that black mullet are good indicators of the oxygen content of the water. If they swim at the surface, you will have to aerate the water vigorously by large-volume spraying through the air. Tarpon are poor indicators of low oxygen conditions, since they can breathe atmospheric air. You may have seen both tarpon and fresh-water gar gulping air during hot summer weather. Certain fishes can live in water of low salinity, if they were in low salinity to begin with. However, marine animals require a minimum salinity of between 28 and 35 parts per thousand. The salinity of the water in the well must be tested at least weekly with a seawater hydrometer.
Q&A 58. I have a queen angelfish, French angelfish, and percula clownfish in my aquarium. Each one will eat its weight in fresh lettuce. Will this much lettuce be harmful for the fishes?
Allowing your fishes to eat as much lettuce as they want will not harm them. In fact, some scientists feel that the lack of plant material is one reason why certain fishes do not survive in home aquaria as well as they do in their natural habitat.
Q&A 59. Would drinking alcohol, if placed in an aquarium, have a drunken effect on small tropical fishes? Also, do you know if there is a new method of treating the parasitic disease Ich?
Alcohol is a poison as is almost anything else used to excess with fishes. Alcohol has been used as a swab with certain external parasites, but not as a cure for diseases that must be treated in the water. Many of the carbon compounds cause a "drunken" effect on fishes, and some are used as an anesthetic. Ich is one of the easiest diseases to cure. Raising the temperature of the water in the aquarium to 85°F will usually cause the symptoms to disappear.
Q&A 60. I have noticed that tropical fish of the same species as one in a small aquarium will grow larger in size in a larger aquarium. What are the reasons for this relationship? Is there any set rule as to what size aquarium is required to grow a certain species of fish to a maximum size?
The populations of any species of fish may differ considerably in their growth characteristics, and these differences are also subject to genetic control. It is characteristic for populations of a species that live in the ocean or run to the ocean to be decidedly larger than populations that are restricted to fresh water. For example, the sea-run lampreys reach twice the size of the lake population. In addition, the growth of fishes may be modified considerably by direct environmental effects. Under aquarium conditions, most fishes do not receive the quantity of food necessary to permit them to grow to their full size. Efforts to increase food supply in an aquarium usually result in fouling of the water and death of the fishes. With most fishes, it is just not possible to provide aquarium conditions comparable to those in the natural habitat. Maximum growth generally cannot be obtained under ordinary aquarium conditions, except with the small killifishes and similar species.
Q&A 61. What is the best way to ship marine tropical fish?
Marine and freshwater tropicals are best shipped by placing them in a plastic bag with clean water and sufficient air space. The bag is tied off by gathering the top together, twisting it and folding the end and wrapping it firmly with rubber bands. Just before closing the top, some shippers fill the bag with compressed air or, better still, pure oxygen. The plastic bag is placed in an insulated cardboard container and taken directly to the airplane for shipment to its destination. The recipient should arrange to meet the package at the airport. Failures of such shipments usually result from overcrowding of fishes or letting the package stand too long at the terminal.
Q&A 62. I have a saltwater aquarium with local tide pool fish in it. I would like to know if any tropical freshwater fish can be converted to 100 percent salt water. If they can be, what is the proper rate of transfer? Could you tell me what species would be suitable for this?
Only a few freshwater tropicals can be converted easily to 100 percent salt water. These are monos, scats, pipefish, puffers, and the archer fish. Some others prefer brackish water (10 to 50 per cent salt): half-beak, Gambusia, mollies and sheepshead minnows. Many of the livebearers can stand considerable salt, and you should experiment with them to find their limits. A 10 percent increase in salinity per week is about right.
Q&A 63. I am attempting to devise a method of counting large quantities of goldfish and tropicals with the least amount of handling. Can you advise me on how to go about it?
Counting large shipments of goldfish and bait minnows is almost always done by sub-sampling. That is, the fish to be counted are size graded by allowing them to pass through a grid of some sort. Then a small sample of fishes of nearly equal size is actually counted, using a wet table, which is usually made of milk glass. If kept cool, most fish can stand being on the table top for over a minute. The table should also have one or more corners cut out, as in a billiard table, to allow the counted fish to be swept into waiting buckets. In this way variable species like goldfish can be sorted for color and type. Fish of approximately the same size are dipped and poured into a count container, usually a quart or gallon bucket, to obtain a level measure of wet fish. These are then counted on the wet table. From 2 to 5 percent is usually added to make up for dead loss. Once a count per unit volume has been obtained it is a simple matter to make up a large order by filling as many buckets as required.
Q&A 64. The “parasites" in the enclosed container have invaded two aquaria and have eaten all the algae growth. 1 would like to know what they are, whether or not they are harmful, and what can be used to destroy them. Copper solution does not seem to have any effect.
The "parasites" you sent for identification are crustaceans called harpacticoid copepods. They commonly infest tanks, reproducing rapidly and causing much damage. They can be harmful in that they crawl on the skin of the fish and chew away at places which can then become infected with bacteria or fungi. At the Rosenstiel School of Marine and Atmospheric Science a solution of 0.15 parts per million of copper is used to control these organisms. It is possible that your copepods have become resistant to this concentration - see if a solution of 0.5 ppm will work. If it does, you can try this on a tank with fish, preferably not your favorites. If they survive, your problem is solved. When these infestations get out of hand, however, it is necessary to sterilize and then dry for several days the tank, the sand or gravel, and all other objects. Then start all over.
Q&A 65. I have 12 tropical fishes that I want to take to our vacation place, which is an hour's drive from my home. Should I transport them in plastic bags filled with well water? Also, how long does it take for mineral water to filter enough to be safe for the fishes?
Tropical fishes are routinely shipped long distances in plastic bags. If the time involved is very great, pure oxygen is added to the bag before it is sealed but, for only an hour or so, this would not be necessary. We recommend that you take some extra well water from home with you. Depending on how much you can take, you might be able to keep the fish in it until the mineral water is filtered, or you might add mineral water to the well water in small amounts over an extended period of time. The idea is to get the fish adapted to the new water in small steps and thus avoid subjecting the fish to too great a physiological shock.
Q&A 66. If I put a cowfish or a filefish in my aquarium, what should I feed them?
Filefishes are nonaggressive, and you should have little difficulty in feeding them; however, they are choosy about their diet. They will always feed on newly hatched brine shrimp, and you may gradually switch to frozen brine shrimp, prawn eggs, and finely chopped squid flesh. The fish will eventually learn to take dried flake food. Cowfishes are also good aquarium fishes and will eat almost anything. You must be careful not to introduce the spiny boxfish into an established aquarium because, if frightened or sick, it will exude a toxic froth at the mouth, killing all your other fishes.
Q&A 67. Does either fluorescent or incandescent lighting affect the reproduction of tropical fishes? If so, how? Do particular colors, such as red, or ultraviolet light have any effect on their reproduction?
Fluorescent lighting has no effect on the reproductive cycle of tropical fishes, nor does incandescent light. There have been some studies made on the effects of different wavelengths, but they are inconclusive. Direct ultraviolet exposure can kill fishes and, to guard against mutation effects, it should not be used directly over tanks even though its penetration depth is very slight. Ultraviolet is also extremely dangerous to human eyes and destroys the cells of the cornea and conjunctiva if looked at directly. It has been found that, in some species of fishes, spawning can be induced by artificially increasing temperature and the length of daylight, or photoperiod. Further information about photoperiod and the importance of it in the lives of organisms is given in "Living Rhythms of the Sea," Sea Frontiers, Vol. 14, No.5, September-October, 1968.
Q&A 68. In my aquarium, I have several baby white anemones that budded off larger ones. Can you offer advice as to how I should feed them?
Regardless of age, healthy sea anemones should respond to food placed with an eyedropper or by hand on their tentacles. The best type of food depends on the type of anemone. Those with short, thick tentacles, which are "sticky" when touched, should be fed pieces of meat or fish. Those with long, slender tentacles usually feed primarily on plankton and, therefore, can be fed either live or frozen brine shrimp. In either case, a small feeding twice weekly is ideal, although a healthy anemone can go for several weeks without food. If the animals do not respond to food placed on their tentacles, this may indicate either that they are satiated or are unhealthy. As a last resort, you might try forcing ground shrimp or fish down the gullet of each one with an eyedropper. Further information can be found in Sea Anemones by U. Erich Friese (T.F.H. publications, Neptune, New Jersey, 1973).
Q&A 69. How do inland public aquariums obtain their natural seawater for their saltwater mammals and fishes?
Most public aquariums located inland use artificial seawater. Among these are Sea World at Orlando, Florida and the John G. Shedd Aquarium at Chicago, Illinois. Formerly, the latter used natural seawater held in reservoirs with a total capacity of 1 million gallons. These reservoirs were replenished periodically by natural seawater brought up the Mississippi River by barge from the open waters of the Gulf of Mexico. With the rising costs of transportation, however, it became more economical for the Shedd Aquarium to make its own seawater by adding 31 tons of salt (with trace elements added) to every 285,000 gallons of freshwater. An electric mixer is used for mixing 600 gallons at a time in a special tank; then the mixture is transferred by hose to the large reservoirs.
Q&A 70. What types of bacteria act as the biological filter in gravel bottoms of marine aquariums? Also, are commercial cultures of these bacteria available for reducing the breaking in time of new aquariums?
The filtering bacteria in the gravel of marine aquariums are mostly of the genera Nistrosomonas and Nitrobacter. To the best of our knowledge, there are no cultures available commercially. The best way of reducing the breaking in time for a tank is to seed the newly laid gravel with a cup or two of gravel from the upper inch of an already established aquarium. The length of time for conditioning the new tank will, of course, depend on its size and the health and density of the seeding culture.
Q&A 71. Would crushed coral be better than beach sand for covering the bottom of my marine aquarium?
Most aquarists use a subgravel filter, since this is probably the easiest and one of the most efficient filtration systems. A subgravel filter operates by pulling impurity-laden water through the gravel on the bottom where the impurities are trapped. If very fine sand is used, a good flow of water cannot be flushed through the filter and, hence, the filtration process is slowed. For this reason, crushed coral is often used, for its porosity allows a faster water flow. Further information may be found in The Complete Book of Saltwater Aquariums by Robert Stevenson (Funk and Wagnalls, New York, 1974).
Q&A 72. I would like to construct a saltwater aquarium of either steel or cement. What type of protective covering could be used to prevent the saltwater from reacting with these materials?
The stainless steels are resistant to corrosion by seawater only as long as the oxide film on the surface of the metal is intact. No other special treatment is required. The nonstainless steels, as a group, will corrode and pit. If your aquarium is to be at all permanent, stainless steel would be best, as there is no completely efficient method for coating nonstainless steel with a protective substance. Chemical attack on concrete is usually by chlorides and sulfates in the seawater. Unfortunately for aquarists, this takes place most rapidly in warm water. To render the concrete impermeable to sulfate attack, cement containing low amounts of tricalcium aluminate (less than 8 percent) should be used. Also, edges and corners should be avoided in the design of your aquarium. Handbook of Ocean and Underwater Engineering by J. J. Myers et al (McGraw-Hill Book Company, New York, 1969) discusses these problems and others associated with the effects of seawater on building materials.
Q&A 73. I have been keeping marine aquariums for many years, but have never been able to figure out why my fishes, apparently healthy, just begin to fade and gradually die. Can you suggest an explanation?
There are several reasons why fishes, for no apparent reason, may die. First, many small fishes only live for one to two years. All the good care in the world will not prevent such fishes from dying. Second, some fishes, such as rock beauties, Holacanthus tricolor, have very specialized diets that are nearly impossible to duplicate in aquariums. While such fishes may live for some time on normal aquarium foods, they almost invariably weaken and die eventually. Finally, trace elements in the aquarium water may be gradually depleted such that the fishes will weaken without them and die. Partial water changes will prevent this, as will avoiding the use of activated carbon as a filter material. The carbon absorbs organic materials, removing them from the biological cycles necessary for a healthy aquarium.
Q&A 74. We are paying a great deal for salt for our aquarium in pet shops. Is there any reason why we cannot use kosher (noniodized) salt to make our own seawater?
While any salt, kosher or otherwise, added to water will make salty water, seawater is a complex mixture of a great many salts besides sodium chloride. In addition, certain elements, called trace elements, are found in seawater in very minute quantities, but are nonetheless very important to the survival of organisms. Gathering all of the necessary salts and these elements and, weighing them out and mixing them in exactly the right proportions is a complicated and, for the average person, expensive proposition. The only substitutes for such work are real seawater and the artificial seawater mixes, such as Instant Ocean. The latter is kept reasonably priced (about $10 for enough salt to make 25 gallons of seawater) because the manufacturers buy and mix the ingredients in large quantities. If you still desire to make seawater, formulas for it are given in some better aquarium books and texts on marine chemistry.
Q&A 75. I plan to enter the marine tropical-fish business. What kinds of problems am I likely to encounter?
There is a large and constantly expanding market for marine tropical fishes, not only in the United States, but in Canada and Europe as well. It is, however, a difficult market to break into, as there are already numerous wholesale dealers in the field. Most sell fishes quite inexpensively, relying upon volume sales for their profits. Collecting large numbers of fishes can be time-consuming, expensive and, if one is not a careful diver, dangerous. There are numerous other problems involved in this business, including fish diseases, death of the fishes before, during, and immediately after shipment (for which the wholesaler is still liable), and establishing and maintaining a constant market. A person entering this market should be prepared to accept small profits, at least initially, and many long hours of work. A good account of collecting methods is found in The Complete Book of Saltwater Aquariums by Robert A. Stevenson, Jr. (Funk and Wagnalls; 1974).
Q&A 76. I would like to experiment on my own with chemical shark repellents. How can I obtain some small sharks, and how difficult will it be to keep them in a home aquarium?
The capture and transportation of sharks, even juveniles, are difficult and specialized tasks that require considerable planning and effort for even moderate success. Despite their fearsome appearance and reputation, sharks are often delicate and require special treatment and complex filtering systems in very large aquariums. An exception is the nurse shark (Gingiymostoma cirratum), juveniles of which sometimes can be ordered through saltwater tropical fish dealers. The 1- to 2- foot juveniles of this species do well in aquariums of 50 gallons or more capacity and feed readily on pieces of fish and meat.
Q&A 77. What exactly are the living rocks that are sometimes kept in aquariums?
"Living" rocks are usually pieces of coral that have died, or rocks honey- combed with holes and tunnels that have been taken over by a host of other marine organisms. They can be found in shallow or deep water, and each rock may have a different collection of organisms associated with it, including many species of algae, tube worms, sea squirts (tunicates), molluscs, anemones, brittlestars, and more. In choosing a living rock for your aquarium, avoid those which contain sponges, because the sponge is a difficult animal to keep and will almost always die, fouling the water. When collecting a living rock, be sure to examine the substrate upon which it was resting, as many shells, brittlestars, sea cucumbers, and sea urchins tend to gather beneath the rock, and they may be included in your collection in the aquarium. Another kind of living rock, sold as a novelty, is a chemical package which, when dissolved in freshwater, produces an elaborate and multicolored precipitate which "grows" over a period of days. Though appearing to grow, there is nothing living about this kind of rock, and the chemicals are hazardous to the animals and plants in an aquarium.
Q&A 78. What is the best method for removing algae from the glass of a saltwater aquarium?
Biological control of excess algae, using algae-eating molluscs, is recommended. If the aquarium does not include such molluscs, algae on the glass can be removed with a sponge on a stick. To remove excessive algae on the gravel, stir it gently; then collect the loosened material in a fine-mesh net.
Q&A 79. Can you provide any tips on how I can make my own air stones out of wood for my saltwater aquarium?
Linden, limewood, beechwood, or malacca can be used in homemade air stones. First, cut a small plug out of the wood and seat it firmly into a plastic block, leaving an enclosed air space under the wood plug. The air space should have a diameter that is slightly smaller than that of the wood plug. Then, drill a hole through the side of the plastic block into the air space and insert the end of the air tube from the air pump into the hole. Check the operation of the bubbler to make sure that air is forced through the wood and not out around the end of the air tube or the sides of the wood plug. Finally, a weight should be attached to the block to keep the bubbler on the bottom of the aquarium.
Q&A 80. Can sharks be kept in a home aquarium? If so, what is an appropriate species?
Most species of sharks cannot be kept in a home aquarium. Many are born too big, or simply grow too large. Furthermore, most pelagic sharks must swim continuously to keep aerated water moving over their gills. Many sharks never learn to successfully maneuver around obstacles; thus, such sharks, if they can be maintained at all, must be held in very large tanks with no obstructions (usually at public aquariums and research facilities). Even then, some sharks have no sense of barriers and will batter themselves to death against the sides of the tank before they learn that they are confined. Species of sharks that usually adapt to home aquariums include the nurse shark (Ginglymostoma cirratum), spotted dogfish (Scyliorhinus caniculus), leopard shark (1riakis semifasciata), smooth dogfish (Mustelus canis), horn shark (Heterodontus francisci), and the swell shark (Cephaloscyllium ventriosum).
Q&A 81. I have a large aquarium of unusual dimensions and have been unable to find an under gravel (subsand) filter that fits in it. How can I construct one?
An undergravel filter plate holds the sand/gravel just off the bottom of an aquarium, allowing water to circulate freely underneath. Any perforated plastic material held off the bottom by spacing blocks will suffice, as long as it fits snuggly into the tank. Corrugated fiberglass roofing panels or translucent plastic panels for fluorescent ceiling lights are both inexpensive and easy to work with. Slitlike holes must be drilled through the plastic. The holes must be smaller than the gravel size so that no gravel falls below the filter plate. Open plastic grids, such as the 1/4-inch-grid "egg-crate" lighting panels, covered with plastic screen also make excellent filter plates. One to several airlifts are fitted into holes in the filter plate; these can be single tubes into which air stones are lowered, or the two-tube variety fitted with a charcoal filter. The filter plate and airlifts are placed in the tank on 1/4- to 1/2-inch spacing blocks and covered with gravel. The airlifts draw water down through the gravel, under the plates, and up the airlift tubes. All the airlifts must be operational and provide a total water flow rate of 1 gallon per minute per square foot of filter area. This flow rate assumes a 3-inch gravel depth, which is considered the minimum depth. By increasing the water flow rate to about 1.5 gallons per minute per square foot, some aquarists manage with only a 2-inch gravel depth.
Q&A 82. I have a live Maine lobster in an aquarium. What should I be feeding it, and how much? Does it need a place to hide? Do I have to regulate the temperature in the tank?
The American, or Maine, lobster (Homarus americanus) will eat almost anything fresh, including its fellow lobsters. It can be fed shrimps, small fishes, or dry fish foods. It does require a high-protein diet and will not eat rotten foods. The American lobster is known to have survived in an aquarium for over three months at 60°F without any food, so overfeeding should be avoided. The lobster should not be fed more than it can eat, and no food should be left in the aquarium for more than 24 hours. The putrification of uneaten food can imbalance an aquarium and lead to the lobster's death. In the wild, the American lobster generally hides from predators during the daytime so, in captivity, even though there are no predators, it may still prefer someplace to hide. In its ocean habitat, during winter when water temperatures can be as low as 29°F, the American lobster hibernates in burrows. The optimum temperature is about 48°F and, as temperatures increase above that, the animal becomes increasingly susceptible to diseases. Given time to adapt, the American lobster can survive in water as warm as 80 degrees Fahrenheit provided the aquarium is well-aerated, but this species is usually kept at or below 65°F to 70°F.
Q&A 83. I have set up an aquarium in my classroom, and one of my students asked: When was sea life first kept in a glass aquarium? Do you know?
The use of glass containers to house marine animals and plants became established in England in the mid-1800s, according to "Victorian England: Birthplace of the Aquarium," Aquasphere, 14(1): 2-7, May 1980. Naturalist Philip Henry Gosse was a pioneer in this work and was largely responsible for the introduction of the term aquarium. His book, The Aquarium: An Unveiling of the Wonders of the Deep Sea, was published in 1854. The first public display aquarium - the Fish House in Regent's Park - was opened in 1853 by the Zoological Society of London.
Q&A 84. I have both fishes and invertebrates in my saltwater aquarium. If I treat the fishes with medication, will it harm the invertebrates in the tank?
Yes. Experts stress that medication should never be used in tanks containing marine plants and live corals or other invertebrates. (A possible exception is low doses of some chlorine compounds.) Invertebrates are extremely sensitive to toxins such as copper and formalin, which may contaminate a tank for a long period of time. Professionals recommend keeping a second, quarantine tank for medicating fishes separately when they become diseased, or for treating new fishes before they are added to the tank.
Q&A 85. What is the proper procedure for transporting marine tropical fishes collected in the Florida Keys to a home aquarium in another state?
Using a small 3- or 4-mil polyethylene bag, the collector should pack each fish individually with enough fresh, clean seawater to allow it to move around. (Two bags are used if the fish has sharp spines or is otherwise able to puncture the polyethylene.) About an equal volume of compressed oxygen is then added to the bag, and the neck of the bag is immediately twisted, folded, and sealed with heavy rubber bands. The next step is to pack the bags in a single layer in an insulated styrofoam shipping container so that they are neither compressed nor loose. Then the container is sealed with tape and clearly labeled for level shipping. Shipping arrangements should be made with an airline experienced in carrying fishes, preferably on an all-cargo aircraft with controlled temperature and ventilation. If the weather is hot, one should select a direct flight at night and make certain that someone will meet the flight on arrival. In general, fishes should not be fed for two days before shipping. A local fish dealer or aquarium curator should be able to answer questions about shipping specific species. Note: Although the Florida Keys are an excellent area for collecting marine specimens for home aquariums, the collector should be aware of basic safety and legal procedures that apply to the area. In Florida, the use of chemicals as an aid to collection is prohibited without a permit. Collection is not permitted in state and federal marine parks, and sea fans and corals are legally protected. Florida law requires that the official Diver's Flag is displayed for snorkelers as well as scuba divers.
Q&A 86. The angelfish I raise seem to go blind after three or four years of age. The fish will not accept food or respond to light or hand movements, and can be touched easily. They have no outward signs of disease or injury. This condition lasts for a month or so; then the fish die. What could cause this puzzling condition?
There are a number of "environmental" aquarium problems that are not "diseases" like parasites or infections, but which over a period of time can cause harmful stress to the fishes in an aquarium and eventually lead to their blindness and death. Usually a combination of things that produce stress are involved, such as excess food, inadequate filtration, poor water quality, excessive variations in pH or salinity, or other chemical and physical factors. According to The Complete Book of Saltwater Aquariums (Funk and Wagnalls, 1974), "If water quality remains bad for a period of time, some fish appear to become blind or unresponsive to conditions around them.” Author Robert A. Stevenson, Jr. says this appears to be triggered by sudden changes, such as temperature variations, that affect fish already weakened by unhealthy water, but not yet showing visible signs of it. Long-term environmental stress, therefore, can cause physiological responses that can disable fish permanently or for long periods of time, even if the water problems have been corrected. If your fish are repeatedly showing these symptoms, a closer monitoring of the water conditions in the tank may be beneficial.
Q&A 87. Is an ultraviolet sterilizer beneficial to a saltwater aquarium?
Yes - under certain conditions. An ultraviolet sterilizer will kill bacteria and protozoa in an aquarium, and is a useful addition to a water system during times of severe outbreaks of epizootic disease. It is also used for routine water treatment in tanks containing organisms that are too delicate to be treated with chemicals. In addition, an ultraviolet sterilizer can help prevent the introduction of infectious pathogens from seawater supplies. Aquarists should keep in mind, however, the fact that an ultraviolet sterilizer will kill the plankton used as food by filter feeders; the sterilizer should not be used if any of these organisms are kept in the aquarium. In Saltwater Aquariums (John Wiley and Sons, 1979), Mystic Marinelife Aquarium director Stephen Spotte expresses his doubts about whether the routine use of ultraviolet irradiation is beneficial in the maintenance of seawater aquariums, since disinfection does not cure, but only aids in controlling disease.
Q&A 88. Whenever I put two fish of the same species in my aquarium, one of them grows larger and becomes dominant, and the other one stays small, gets ragged-looking, and usually dies first. Why is this so, and can the problem be prevented?
It seems likely that your aquarium fish are not being provided with hiding spaces. It is normal for most fish to be territorial and aggressive, and each fish needs its own structure - a hole or recess - to hide in. Fish often grow at different rates, even those hatched from the same spawn. The larger fish will naturally take the best living space and the most food. This is part of the survival of the fittest. You must ensure that the smaller, competing fish has a hiding place as far away from its antagonist as possible and that it get its share of the food by placing some specially in front of its home, if necessary.