A little stickleback fish (Gasterosteus aculeatus) nicknamed "Mary" appears to have leaped across a major reproductive divide on the evolutionary tree of life. Stickleback females, like most female ...

Male fish are turning into females thanks to chemicals from birth control pills and makeup being flushed down drains, according to a new study. The study of freshwater fish in Britain found a fifth of ...

Add Yahoo as a preferred source to see more of our stories on Google. The fish swimming in the streams, rivers, and lakes around your town are probably on Prozac. Now new research from the U.S.

(PhysOrg.com) -- A 380-million-year-old fossil fish that shows an unborn embryo and umbilical cord has been discovered, scientists report in the journal Nature. The extremely rare specimen shows ...