See a close-up of the deep-sea dragonfish’s transparent teeth.

A fossil of a school of fish from the Eocene appears to represent coordinated collective movement.

The silver spinyfin has an extraordinary diversity of rod photopigments, which researchers propose may allow it to see color in the deep, dark sea.

Gulf killifish have made a stunning comeback in Houston with the help of genetic mutations imported from interspecies mating with Atlantic killifish.

Fossils reveal the quick death of plants and animals from a massive surge of water after the impact 66 million years ago, which is thought to have spelled the demise of dinosaurs.

Nearly 50 years after its development, only a handful of creatures have passed the self-awareness exam. A new attempt with fish highlights a debate over the test’s use and meaning.

Freshwater fish suffer from low levels of oxygen in the country’s rivers, while bats are unable to survive the extreme air temperatures.

From cellular self-digestion to the effects of exercise on the brain, our features editor picks her favorite art custom-made for the magazine.

Fish scales follow a model famed computer scientist Alan Turing developed to describe patterns observed in other animals’ feathers, spines, and scales.