Fish are cold-blooded vertebrates.

They inhabit diverse aquatic environments, including freshwater and saltwater.

There are over 33,000 known species of fish.

Fish have scales covering their bodies for protection.

Gills are the respiratory organs of fish, allowing them to extract oxygen from water.

Some fish species can breathe air using a labyrinth organ or modified swim bladder.

Fish come in various shapes, sizes, and colors.

The largest fish is the whale shark, which can reach lengths of over 40 feet.

Fish play a crucial role in aquatic ecosystems as both predators and prey.

Some fish, like the clownfish, form symbiotic relationships with sea anemones.

Fish exhibit a wide range of behaviors, including schooling, mating displays, and territorial defense.

Electric fish, such as electric eels, can generate electric fields for navigation and communication.

Fish use their fins for maneuvering, balance, and propulsion.

The lateral line system in fish helps them detect water movements and vibrations.

Fish have a two-chambered heart that pumps blood to the gills and the rest of the body.

Many fish species lay eggs, and some exhibit elaborate courtship rituals.

Some fish, like salmon, undergo long migrations for spawning.

Certain fish, such as angelfish, are popular in the aquarium trade.

Fish are a significant source of protein for human consumption.

Overfishing is a threat to many fish populations and marine ecosystems.

Fish communicate using visual signals, sounds, and chemical cues.

Some fish, like the mudskipper, can survive out of water for extended periods.

The coelacanth is a rare and ancient fish species known as a living fossil.

Fish have taste buds all over their bodies, not just in their mouths.

The pufferfish can inflate itself to deter predators.

Certain fish, like the archerfish, can shoot water jets to knock insects into the water.

The lionfish is an invasive species known for its venomous spines.

Fish fins have specific names, including dorsal, anal, pelvic, pectoral, and caudal fins.

Some fish, like the parrotfish, can change their sex during their lifetime.

Fish exhibit various feeding strategies, including filter-feeding, herbivory, and predation.