I have a freshwater 20 gallon tank with mostly snails and two gourami fish. Earlier today I noticed a tiny silver thing (about the size of a grain of rice) seemingly swimming around. On closer investigation I saw that the small thing had a tail and fins, eyes, and a shell. Is it possible that my gourami and one of the larger snails did what animals do (mated)? I am utterly perplexed. Thoughts?