Giant salamander

Giant salamanders are very big.

They live in the water. Most of them walk on the bottom. They are not fast swimmers.

These animals hunt at night. They eat fish and crabs. They cannot see well. They feel tiny changes in the water to find food.

They have large folds of skin. These skin folds help them breathe. They take in air from the water.

Some live in China and Japan. Others live in the United States.

One kind can live for 50 years.

They are amazing creatures of the water.

Giant salamanders are very large animals. They live in the water. Most stay in China, Japan, or the United States.

These animals are not fast swimmers. They mostly walk on the bottom of the river. They have thick bodies and heavy tails. They also have large folds of skin. These skin folds help them breathe. The folds take in oxygen from the water. This is important because adults have poor lungs.

Giant salamanders hunt at night. They eat fish, crabs, and shrimp. They have bad eyesight. To find food, they use sensory nodes. These are special spots on their skin. They feel tiny changes in water pressure to find prey.

During mating season, they move upstream. A female lays over 400 eggs in two strings. The male guards the eggs for three months. He may use his tail to fan the eggs. This helps bring more oxygen to them.

Some of these animals live a long time. A Japanese giant salamander lived for 52 years in a zoo.

Giant salamanders are some of the largest living amphibians on Earth. These huge creatures belong to a group called Cryptobranchidae. They live entirely in the water. You can find them in China, Japan, and the eastern United States. One special type is the hellbender. It lives in the United States and is the only one in its genus.

These animals have a very interesting way of breathing. Most adult giant salamanders have poor lungs. They also lack gills, though some still have gill slits. To get oxygen, they use large folds of skin on their sides. These skin folds increase their surface area. This helps them absorb more oxygen directly from the water. They are not fast swimmers and mostly walk on the river bottom.

Finding food is a hard job because they have bad eyesight. They are mostly nocturnal, which means they are active at night. To hunt, they use sensory nodes on their heads and bodies. These nodes feel tiny changes in water pressure. This helps them find fish, frogs, crabs, and shrimp. The Chinese giant salamander eats many of these aquatic animals.

Giant salamanders have a very long history. The oldest fossils come from the Middle Jurassic period in China. One fossil was found by Johann Jakob Scheuchzer in 1726. He thought it was a human from a great flood. Later, Georges Cuvier realized it was actually a salamander. The genus Andrias was named by Tschudi in 1839. This name means "image of man."

These animals can live for a very long time. A Japanese giant salamander once lived for 52 years in captivity. During mating season, they travel upstream to spawn. A female can lay two strings of over 200 eggs each. The male stays to guard the eggs for at least three months. He might even fan his tail to bring more oxygen to them.

Giant salamanders belong to the family Cryptobranchidae. They are among the largest living amphibians in the world. These animals are fully aquatic, meaning they spend their entire lives in the water. You can find them living in China, Japan, and the eastern United States. Within the larger division of salamanders called Cryptobranchoidea, they are one of two living families. The other family is the Asiatic salamanders, known as Hynobiidae.

The way these animals breathe is quite unique. Most adult giant salamanders have poorly developed lungs. They also lack traditional gills, though they show paedomorphic traits. Paedomorphism means they do not complete a full metamorphosis from larvae to adults. Because of this, adults often retain gill slits. To compensate for their breathing needs, they have large folds of skin along their flanks. These folds increase the animal's surface area. This allows them to absorb more oxygen from the water through capillaries in the skin. This process is why the family name comes from the Greek words for "hidden" and "gill."

There are different types of giant salamanders found in different regions. The genus Andrias contains the largest species and is native to East Asia. One example is the South China giant salamander, or Andrias sligoi. Another is the Japanese giant salamander, known as Andrias japonicus. This species can grow quite large and has been known to live for over 50 years in captivity. In the United States, you will find the hellbender. The hellbender belongs to the genus Cryptobranchus and is the only member of that specific group.

These salamanders have a very long evolutionary history. The oldest known fossils of cryptobranchoids date back to the Middle Jurassic in China. A creature called Chunerpeton is suggested to be one of the oldest. Over millions of years, these lineages moved across the world. Scientists believe they reached the eastern United States via a land bridge. This process allowed them to spread through adaptive radiation.

One famous moment in their discovery involved a Swiss physician named Johann Jakob Scheuchzer. In 1726, he described a fossil that he believed was a human drowned in a biblical flood. He called it Homo diluvii testis. However, in 1812, Georges Cuvier examined the fossil and realized it was not human. It was actually a salamander. It was later renamed Salamandra scheuchzeri in 1831. In 1839, Tschudi coined the genus name Andrias. This name means "image of man," which honors Scheuchzer's original mistaken belief.

Feeding and survival require special adaptations. Giant salamanders are mostly nocturnal, so they hunt at night. They have very small eyes and bad eyesight. To find food, they use sensory nodes on their heads and bodies. These nodes detect tiny changes in water pressure. This helps them locate prey like fish, frogs, crabs, and shrimp. While they are aquatic, they are actually poor swimmers. They usually walk along the bottom of the water. They only use undulatory locomotion, or wavy body movements, for short escapes.

Reproduction is a dedicated process for these animals. During mating season, they travel upstream to spawn. A female can lay two strings of eggs, with each string containing over 200 eggs. The male fertilizes the eggs externally by releasing sperm onto them. He then guards the eggs for at least three months until they hatch. The male may also use tail fanning to increase the oxygen supply for the eggs. Only large males can occupy and guard a den. They protect the den from other males and inactive females.

Today, these animals face challenges in their natural habitats. In Japan, dam-building threatens their environment. To help, some dams have been fitted with ramps and staircases. These allow the salamanders to move upstream to their spawning areas. Understanding their biology and history helps us protect these ancient survivors. Their presence in our rivers connects us to a lineage that has existed for tens of millions of years.