Fish can form schools containing millions of fish. They use their eyes and something called a lateral line to hold their places in the school. The lateral line is a row of pores running along the fish’s sides from head to tail. Special hairs in the pores sense changes in water pressure from the movements of other fish or predators.
Some desert pupfish can live in hot springs that reach temperatures greater than 113° F.
Most fish have little salt in them. Sharks, however, have meat as salty as the ocean they live in.
A male emperor angelfish lives together with up to five female mates. If the emperor angelfish dies, one of the females turns into a male fish and becomes the leader of the group.
Most brands of lipstick contain fish scales.
The mudskipper is a fish that spends most of its time out of water and can “walk” on its fins. It carries a portable water supply in its gill chambers when it leaves the water. It can also breathe through the pores of its wet skin.
Most fish can see in color and use colors to camouflage themselves or defend themselves and their territory. Most fish have the best possible eyesight for their habitat and can most certainly see you peering at them in a fish tank. Some fish can see polarized and ultraviolet light.
Starfish are not fish. Neither are jellyfish.
There are approximately 32,000 different kinds of fish in the world today, which is more than all the other kinds of vertebrates combined. Scientists are discovering new species all the time.
A fish does not add new scales as it grows, but the scales it has increase in size. In this way, growth rings are formed and the rings reveal the age of a fish.
Sometimes tornadoes pick up fish while traveling over water and carry them over land, where the fish rain down. These “fish showers” have been happening for thousands of years. Roman writer Pliny the Younger describes this phenomenon in the 1st century A.D.
The batfish plays dead when danger is near. It floats motionless on its side when scared, making it look like a dead leaf floating on the surface of the water.
Male anglerfish are much smaller than the female. While the female can reach up to 24 inches long, the males barely reach 1.6 inches long and live as parasites on their mates. They stay together for life. As the male ages, he gets smaller and smaller. The female anglerfish’s light is always “on.”[
Anableps, four-eyed fish, can see above and below water at the same time.
Most fish cannot swim backwards. Those that can are mainly members of one of the eel families.
Scientists have explored only 1% of the ocean depths. They believe millions of new kinds of animals and fish are down there, waiting to be discovered.
Empty dogfish egg cases sometimes wash up onto the beach. Some people call them mermaid purses.
The fish in the middle of a school control the school. The fish on the outside are guided by those in the middle. Only bony fish can swim in highly coordinated groups.
Catfish have over 27,000 taste buds. Humans have around 7,000.
Humans have been amazed for centuries that salmon, after journeying across the ocean, can find the river where they were born. In the Yukon River in Alaska and in Canada, certain tagged Chinook salmon covered nearly 2,000 miles in 60 days. Salmon also have adapted to live in a variety of aquatic environments, including rivers, lakes, estuaries, coral reefs, and the open sea.
A baby seahorse is called a "fry."
The term “fish” is used when referring to one species of fish (e.g., 10 salmon are 10 fish). The term “fishes” is used when referring to more than one species (e.g., 10 salmon, 3 trout, and 1 angel fish are 14 fishes).
Unlike most other fish, the ocean sunfish does not have a tail. A female sunfish can lay 300 million eggs each year. Each egg is smaller than the period at the end of this sentence.
A seahorse can move each of its eyes separately. One eye can look forward while the other looks backward. Seahorses can also change their color to match their surroundings.
Lampreys and hagfish are the most primitive form of fish still living today.
The freshwater Pygmy and Luzon gobies of the Philippines, the saltwater Marshal Islands goby, and the tiny rice fish from Thailand all reach a maximum length of 1/2", roughly the size of a grain of rice. They are typically considered the world’s smallest fishes.
Most types of seahorses pair for life. Female seahorses lay their eggs inside a pouch on the male seahorse’s belly. When the babies are ready to hatch, the male holds onto a piece of seaweed with his tail and rocks back and forth until the babies pop out of his pouch.
Hagfish are some of the slimiest animals on earth. An Atlantic hagfish can make enough slime in one minute to fill a bucket.
Fish were the first vertebrates with bony skeletons to appear on Earth. Unlike today’s fish, early fish had no scales, fins, or jawbone, but they did have a dorsal fin.
Unlike bony fish, sharks and rays do not have swim bladders. They have to swim all the time, even when they are sleeping. Otherwise, they will sink to the bottom of the ocean.