/www.aquariacentral.com/articles/zebradanio.shtmlso if the female looked fat she was probably ready to spawn. It also says they are egg scatterers and that if they did spawn you should see eggs "sprinkled" all over the tank. Maybe it was a snail? do you have pond snails in the tank? Do you have any other fish other than the danios?Mature Zebras are very easy to sex, males are very slim and the females when ready to breed are very heavy. If your female is not noticeably heavy she is not ready to spawn. Just keep them in your community tank and feed well until she gets in condition.