Some scientists believe that there may be groupers that live to be 80 to 100 years old. Some species of fish living in freshwater caves have been underground so long they've developed without eyes. The same is true of a fish, called the blind goby, that lives in shrimp holes. These fish use other senses to navigate and find food. Fish don't have any outer ears, but they can hear.
Sound waves strike the fish's inner ear.
The dwarf pygmy goby, found in freshwater lakes and streams on the island of Luzon in the Philippines, was thought to be the smallest fish in the world. It measured less than half an inch when full-grown. But, in 1981 scientists discovered a species of marine goby where the female was fully grown at just under a quarter of an inch. All Rights Reserved.