Add Yahoo as a preferred source to see more of our stories on Google. Most animal species reproduce sexually. This involves the fusion of two gametes, the sperm and egg, that develops into an embryo.

Reproduction in animals varies from species to species. Some types of reproduction, like parthenogenesis, are more unusual than others. This reproductive method requires only one individual rather ...

It may sound too bizarre to be true, but the Amazon molly (Poecilia formosa), a fish that inhabits rivers, lakes, and swamps ...