Last friday, 8 days ago, I adopted a 10 gallon aquarium with a load of baby fish, the owner said she did not know what the mother fish was, that she had just got the tank and mother fish for her birthday and the fish died after all these babies showed up in the tank. She never said anything about a second fish, so I assumed a livebearer, such as guppies. The tank water was pretty dirty and smelly with some dead fry in the muck in the gravel. I cleaned up the tank and rinsed the gravel and sponge filter and restored the retained water back to the tank, pouring it through a coffee filter over a sieve. The tank had no hood or light, just a bed of gravel, plastic plants and a sponge filter. I managed to collect 176 live baby fry and after a week the largest are about 1/2 inch long and the smallest still look like new fry. I set up my 29 gallon tank with a power filter and filter stone going, a bed of gravel and a few of the plastic plants from the 10 gallon tank and a bit of the water from it. Did that the day I brought the fish home. When I do the water changes, I remove an equal amount from the 29 and put the same from the 10 into it and refill the 10 from what I took from the 29 and all the fry seem healthy, but for those tiny ones. I figure on putting the biggest ones into the 29 and am going to set up my 20 for the next size to mature, letting any stragglers develop withoug being harassed by the larger ones. I had joined a guppy forum, thinking that they were guppy fry, but after looking at pictures of guppy fry, they were wrong, they had forked tails, unlike guppies or the other live bearers, so I changed my tactic and went to an overall aquarium forum where they suggested that it was some kind of tetra and after much research the only tetra without an adipose fin was the silver tip tetra. Only one local pet store had a silver tip tetra and just one. Is there any other tetra without the adipose fin?