Japan is an island nation surrounded by the ocean. Fish are deeply familiar to us, yet they hold many mysteries and possibilities—from their ability to change sex depending on environmental conditions ...

In mosquitofish, of the genus Gambusia, male fish are smaller than females -- sometimes only half the size. Biologists had previously assumed that smaller male mosquitofish had at least some ...

Polar fish experience lower mortality than tropical fish, allowing them to delay reproduction until later in life when they are larger and can produce more eggs, according to a study by Mariana ...

The ocean is home to a vast array of different animals, each with its own traits. These include different forms of mating, such as parasitic mating. Parasitic mating occurs when the male physically ...