Interesting fish facts

August 18, 2009 | In: Animal facts for kids

There are over 25,000 identified species of fish on the earth.

Fish have been on the earth for more than 450 million years.

When a fish is caught on a hook and line, it can definitely feel through its nervous system that it has been hooked, and will try to escape. Unlike humans, most fish have no frontal lobe in their primative brains and so they are not likely to be distressed by what they feel.

All fish are cold blooded, which means their body temperature is tied to the water around them.

A single piranha can’t eat a man, but it can take off a toe.

Most fish do not have eyelids, so technically they cannot close their eyes to sleep. They do however rest in different ways: many eat and swim during the day and remain inactive at night, while some are always semi-resting (daydreaming) as they virtually spend their whole lives motionless.

Fish have no outer ears but enclosed organs situated on either side of the head behind the eyes that respond to sound waves in the water.

Fish move by creating a wave motion that moves the length of its body.

There are three classes of fish: jawless, cartilaginous, and bony.

All salmon die after they spawn, but some steelhead can spawn more than once. After spawning some
steelhead return to the ocean and come back again to repeat the process.

The sailfish is the fastest fish in the sea. It has been clocked going just over 68 miles per hour (about 110 km/hour)

The South American marbled hatchetfish are the only fish that can achieve powered flight. Unlike other flying fish, which simply glide through the air, the marbled hatchetfish can fly by flapping their pectoral fins very rapidly, making a buzzing noise!

These fish have deep chest cavities and huge pectoral muscles for powering their long fins, and can make brief flights up to five feet (1.5 meters) to escape predators.

Bluefin and bigeye tunas have highly developed heat exchange systems to keep their blood up to 20 degrees warmer than the water! So do requiem sharks and (it is suspected) several other kinds of large fish predators.

Having warm blood is important for these fast, high-metabolism fish because they need to hit top speed quickly when chasing prey, even in cold water. They are predators near the top of the ocean food chain, normally preyed on only by killer whales, sharks, and humans.