I finally get to write about my first fish observation.
I have a small community tank that by book standards is overcrowded but I haven't had any problems with it. A few months ago one of my Red Velvet Swords gave birth to about 75 young and before long they had to be moved to another tank so l set up a 29 gallon tank that l kept the water level at three quarters full. The reason for this is I've had too many Swordtails jump out of a tank in the middle of the night.
I read in an article of Freshwater and Marine Aquarium magazine about using beef heart as a fish food and reading how easy it was to make I decided to try it. At first I planned to feed this new food only to my larger Oscars but I put a small piece into my baby sword tank and they devoured it. By mixing this food with brine shrimp and flake food, I noticed an increase of size in these small fishes. Oh-oh, I'm getting off track of the fish story.
I lost nearly 55 of my starting 75 Swords to a disease I still can't figure out.
Being the beginner that I am, I didn't record the date of the little ones' birth but after 2-3 months changes began to happen in the tank. Swordtails, when growing up, look as though they are all going to be females. I noticed that one day after a feeding of brine shrimp one of the baby Swords may have been coming down with some sort of disease. It's body was contorted and his eyes were bugging out similar to a celestial goldfish. I decided not to treat the tank.
When I checked on the tank the next day, to my surprise all the fish looked normal and none were dead. Two days following this episode I noticed that one of the swords was growing a tail. I have a son. I remembered back to the fish that was suffering and determined that this new male fish was actually the half dead fish I was going to feed to my other fish.
You may be wondering how I came to that conclusion. Out of the remaining 20 babies that I had, 10 were pure orange/red, 5 were half orange/red and half white, and 5 were pure white (they are not albinos because the eyes are not red). The fish that I saw suffering was one of the larger pure white fish. I have since watched the tank every day to see if I could spot any new developments. I have watched two more of the Swords go through the puberty stage. First comes the appearance of the male's gonopodium. Next, the body begins to lengthen in the tail area, then the actual tail begins to grow into a Swordtail. The other two swords who are going through this phase also showed a small amount of contortion of the body and a slight bulging of their eyes, but not to the extent the first one I viewed went through. It may be interesting to watch over the next week or more how many of the supposed females turn into males.