Hybrids...good or bad?

[clothahump]

Removed, I did not start this thread.
Clothahump: I split this thread off from the Panda corie thread

[Teelie]

If you want them to interbreed, let them. Despite the above post, who apparently doesn't know much about crossbreeding in nature, it happens alot. Usually the eggs are infertile or the offspring are anyways so the "new" species is a limited one.

So long as the offspring are not introduced into the wild or physically deformed, I can't see why it matters.

[clothahump]

I bow to your superior knowledge on the genetics of fish, could you explain where and which species interbreed in Nature? I would be very interested in you writing this up as an article for my website.

[Teelie]

I don't have time for superiority complexes like yours so I'll suggest you learn how to google.

But since you need someone to do your work for you, I will say this, if you knew anything of genetic history, you'd realize many animals, fish included, die out in part because they interbreed and become a new species or fold into an existing one.

There is also the reverse where a species diversifies when one environment splits into two environments and becomes two or more species. Basic college biology courses teach this kind of thing.

Now explain just what the dangers of interbreeding tank raised hobbyist fish are and why it's this great evil? Never heard of a goldfish? Those are a mix breeding of carp species from centuries ago and then further bred into a dozen or more body shapes. No outcry for that "frankenfish" to my knowledge..

[Fishnut2]

Please keep things under control **** ****I think this is an interesting topic, and I might split it off into another thread if we get a few more opinions. Personally... I keep all single species tanks. As a breeder, I want to avoid hybrids at any cost. I will mix species during grow out...but when it's time to breed, I want to keep my lines pure! Any other opinions ****

[clothahump]

I don't have time for superiority complexes like yours so I'll suggest you learn how to google.

I think I have the hang of this now, so if I use Google it will answer the question of why you think it is OK to hybridise fish?
I run my breeding program the same as Fishnut2, keep the species pure at all costs, hybrids are not wanted in the hobby and do not occur in the wild, if however you know of a species that naturally hybridises with another species please let us know.

[Teelie]

Still haven't been given an explanation why they are bad in the hobby. Just because you don't want hybrids, you don't want anyone else to have hytbrids either is pretty much the sum of your arguement to me.

Anyhow, I'll abide Fishnut2 and let it drop. I doubt you'll give a clear answer why they're so dangerous when you ignore the question.

[clothahump]

I would hate to see them interbred as the way things are going in the Amazonian region the natural habitat will all be destroyed so we can eat Beef Burgers, Soy and Sugar, that will leave us the hobbysists with ensuring the species survive until such time they can be released back into the wild somehow.
If we allow Hybrids to become part of this we destroy species not create them, that job is best left to nature.
Could you let me know the species of fish that naturally hybridise in the wild?

[shev]

ok, so interbreeding would be the opposite of inbreeding? inbreeding is usually used for isolating certain traits, but has less genetic deiversity causing many problems. a species would be a group of animals that could breed and produce fertile offspring, are interbred corys fertile? or are they like donkeys? are the different human races are subspecies or homo sapien sapiens? whats wrong with hybrids, they would have more genetic diversity. subspecies are still all the same species, i used my "google skills" to look up what it meant. "(biology) a taxonomic group that is a division of a species; usually arises as a consequence of geographical isolation within a species."
so they are on their way to becoming a new species. i guess it would be unnatural to interbreed them.... but are these subspecies found in the amazon and surrounding tributataries? for as long as the subspecies are inbreeding with pure bred corys in aquariums they are becoming less like the natural ones in south america.

kinda like the different kinds of dogs, they all came from wild dogs/wolves.

[Teelie]

Tell me, do all the fish that are interbred no longer exist now that their offspring are around? We have blood parrots but sevrums and red devils aren't gone. Why would the same happen to cories or other fish? Like I said before, most of the time the eggs or offspring are sterile anyways so there is no reproduction of that hybrid. Pretty much ensures there will never be an extinction of that species so long as there are die hard breeders out there either.

Which fish interbreed in the wild? I'll get back to you on that with a list.

In the meantime, here's some urls to chew on while you pontificate over the evils of hybrdization.

Stabilizing selection on genomic divergence in a wild fish population

And to sate your demands at least somewhat:

Hybrization between fish species in nature. PDF file. States "He soon noted that natural hybrids occurred in many collections. This observation was in conflict with the teachings of his mentor, David Starr Jordan."

Plus:
http://members.optushome.com.au/chelmon/Hybrid.htm

There have been some reports of 'natural' rainbowfish hybrids being found in nature. Gerald Allen has found a couple of hybrids in the wild and several others have caught an occasionally hybrid. However, most of these natural hybrids are rare.

This one shares your same good intentioned if misguided ideals on "purity" in the genepool, totally ignoring the implications of reduced genetic diversity.

[Lisachromis]

Originally Posted by Teelie @ Tue Feb 22, 2005 3:09 pm I Never heard of a goldfish? Those are a mix breeding of carp species from centuries ago and then further bred into a dozen or more body shapes. No outcry for that "frankenfish" to my knowledge..

Umm.. goldfish are one species. Not a crossed species. Since it's been played with by man for so long, it has many mutations available.

And just so you know, many fish crosses are viable and will produce viable young. This muddies the genetics of the fish in question. Most dedicated hobbyists prefer to keep pure species. When you cross them, you confuse the genetics. It's not always easy to know when you've gotten a crossbred fish. If you really can't cull any fry you get from the fish, you should always tell people that they are crossed. That brings up another problem. Say you are honest enough to tell people that buy them that they are crosses. Maybe the people you are selling to aren't that honest.
So, the best route is to not let the fish you do have crossbreed. If they do, you really should cull the fry. Please don't try to cross your fish! This is why crosses are bad for the hobby.

[Teelie]

Read the edited information I added above. If anything, hybridization is better for a species in the long term especially in the aquarium. With a captive raised gene pool, you have a severely limited and restricted genetic history which weakens the species overall.

Of course this will fall on deaf or unaccepting ears but it's worth a shot to at least attempt to clarify the irony of who is more detrimental to a species' health.

[Lexus]

This all should have been in a new fresh topic, maybe the moderator will move half of it

[Fishnut2]

Good point Lexus! I mentioned earlier that I might move it into a new topic. I'm a new mod (here) and don't want to screw it up. I'll ask Mark for help to split the thread. I appreciate that others have joined in, as I think it's a great topic. I'll post a bit more of my opinion, once I get it moved. In the meantime...keep posting

[Fishnut2]

OK,
****I took a chance, and actually did it right! (This thread was split from "Panda cories")
A good point that Teelie made, was about the deteriaration of the genetic lines from breeding captive fish. Good breeders will go out of thier way to obtain different bloodlines, in order to keep thier strains strong. I agree that linebreeding (related fish) will eventually produce cull fish. Even if they aren't culls, thier genetics won't be as strong as breeding with diversified stock. A perfect example of this were the albino bristlenose plecos. When they first hit the hobby (around here anyway) there was a limited availability. Many people bred related stock, as that was all that was available. There were a lot of fry that had crooked tails as a result of this line breeding. Now that different bloodlines are available...the crooked tails have become fairly rare.
**** I'd also like to talk about selective breeding. (Breeding for a certain trait) Long fin bristlenose plecos are a good example for this. They aren't a hybrid (crossed with a different species). They were probably linebred originally, for the desired trait...the Long Fins. This is common with guppies/angels/goldfish/koi...and probably many other fish. This is also common with breeding dogs. My dog was line bred for the excellent OFA (hip rating). When I mated him...I found a female from a different pedigree with an excellent OFA...which is an example of selective breeding.
**** Now for my opinion on breeding fish! It's just an opinion, and doesn't mean I'm right or wrong **** ****I'm totally against hybrid fish. I don't have a problem with selective breeding. I would only linebreed if that's the only stock available...and it's a rare fish. (My black aeneus are the only fish I've ever linebred).
**** PLEASE post your opinion. I'd love to hear from ya ****