Dec 21, 2025 · A fish is any of approximately 34,000 species of vertebrate animals (phylum Chordata) found in the fresh and salt waters of the world. Living fish species range from the …

A fish is an aquatic, anamniotic, gill -bearing vertebrate animal with swimming fins and a hard skull, but lacking limbs with digits. Fish can be grouped into the more basal jawless fish and …

May 21, 2024 · Learn about fish in biology. Get the fish definition, see examples, and discover the characteristics of these aquatic animals.

What is a Fish? Fish and Fishes Fish are aquatic vertebrate animals that have gills but lack limbs with digits, like fingers or toes. Recall that vertebrates are animals with internal backbones. …

Sep 25, 2025 · What are fish? What are the main types of fish? What roles do they play in aquatic ecosystems? Discover their definition, key characteristics, classification, and feeding behaviors.

Fish Discover the fascinating creatures that inhabit our vast oceans. These cold-blooded vertebrates have gills, which are specialised organs allowing them to breathe underwater.

Fish are extremely diverse animals that live in a variety of freshwater and saltwater habitats all over the world. This website is dedicated to helping you learn about fish biology, physiology, …

Explore facts and photos about fish found in and around the United States. Learn about their range, habitat, diet, life history, and more.

Fish facts: There are over 33,000 different types of known living fish species! This is greater than the total of all other vertebrate species combined!

Fish evolved in fresh water; the chondrichthyes moved to the sea early in evolution, while the bony fishes went through most of their evolution in fresh water and spread to the seas at a …