To survive in a competitive world, some guppies are born not just bigger, but also more mature. To help offspring survive, some moms engage in a kind of trade-off: Churn out a bevy of offspring and ...

When you run an aquarium, sometimes the fish in it will have babies, but depending on what type of fish you keep, those babies are likely to get eaten. What would you do if a family friend asked if ...

A friend of mine decided to get a group of children in her care a fish tank and guppies as a “class pet.” The guppies were soon joined by baby guppies. The babies disappeared, one by one. Turns out, ...