I cant tell if my sword tail is over feed or pregnant i had her in breeding tank for a week with the male and after a while i noticed she would get bigger and bigger and fatter and fatter. i have picture but dunno how to post.
It's a safe bet that she is gravid, which is the word we use for "pregnant" when talking about these fish. As she gets fatter and fatter, the lower rear part of her abdomen, where the anal fin attaches, will get stretched and turn clear. In guppies the inner linings can be seen which makes this clear spot look black, but in swords and platies it's usually just a darker shade of whatever color the fish is. Well, I take that back; in platies thay can be dark and blackish, but in swords a reddish brown is often all you get. At any rate, this spot is called the "gravid spot" and it's a very good way to see that your fish is gravid. As the developing fry grow, the abdomen will bulge more and more, and eventually you'll likely be able to see tiny little eyes looking back out at you through the gravid spot. That's when you know that delivery time is very near. Don't count on it, though, for often they give birth without any warning at all.