Over the past 160 million years, giant salamanders (Cryptobranchidae) have hidden under rocks, channels and streams, and they have survived well and evolved into one of the largest amphibians in the world.
Led by the mainland South China salamander (Andrias sligoi), the highest length record reached 1.8 meters. The recorded specimens were captured near Guiyang, Guizhou Province in the early 1920s, and most are much smaller today.
Ancient species across the world
Cryptogill salamanders are actually large salamanders - aquatic amphibians.
Giant salamanders are known to make sounds, bark, wail, hiss, or cry. Some of these sounds bear a striking resemblance to the cries of human children, hence the origin of the name baby fish.
And from a natural history point of view, the giant salamander is one of the most special vertebrates on Earth. They are very strange and weird, with thick bodies dragging heavy big tails - rudder-like tails, a wide and flat head, and an ugly face that grandma does not love uncle.
Oh, by the way, a little more: the salamander's tail, although like a rudder, is almost never used for swimming. These large salamanders use their toes to pick rocks at the bottom of the river, walking back and forth in streams instead of swimming...
Salamanders still retain gill slits (although they also have lungs) as adults, with large skin folds on the sides of their bodies, which help increase surface area and allow them to absorb more oxygen from the water.
The oldest known fossil of cryptogill is from the mainland, around the Middle Jurassic period, and they have lived to this day without much change.
Although they all look similar, however, a study published in 2018 pointed out that the Chinese giant salamander is actually composed of many evolutionary branches limited to different watersheds, some of which are so unique that they can be considered independent species, and since then there have been representatives such as the South China giant salamander and the Jiangxi giant salamander.
Interestingly, while the fossil record undisputedly shows that this family originated in Asia, they are also found in the eastern United States. This has been the focus of scientific attention — perhaps similar to how humans got from Asia to the Americas — through land bridges, and adaptive radiation waves appear to have swept through the Americas from north to south.
"Boring" reproduction like a fish
The breeding of giant salamanders is as fun as fish.
They do not have any form of courtship, let alone any mating position: the female salamander lays more than 200 eggs in a row on her own, and the male fertilizes the eggs by releasing sperm onto the eggs, and then becomes a good father - guarding the fertilized eggs for at least three months until they hatch.
For young salamanders who leave their father's care, finding suitable housing is not just a major life decision, but a key to survival.
In waterways, salamanders occupy a specific ecological niche – both predators and prey – and even salamanders devour each other.
This is very helpless, because juvenile salamanders have huge differences in size during the growth stage, plus the species will eat almost anything that can be put in the mouth and swallowed - aquatic insects, fish, frogs, crabs and shrimp, due to poor vision, salamanders use sensory nodes on the head and body to detect small changes in water pressure - will move? Swallow it first, call it a relative or not.
Therefore, the giant salamander evolved a corresponding way of self-preservation: when it was a child, it "got" under a small rock, and gradually moved under the larger rock as it grew up. It is important to choose a stone at the bottom of the river that is "tight and just right" - to save yourself from being attacked and eaten by a neighbor who is bigger than yourself.
Remember the funny story in the fairy tale where a lost little girl enters the bear's house and finds three sets of cutlery and beds? Life in a giant salamander is pretty much like that.
Write at the end
It is precisely because they are ancient and have not changed, giant salamanders are experts in that very special type of environment. Their success depends on the constancy of dissolved oxygen, temperature and flow in fast-flowing waters, which limits their range to narrow streams/rivers.
Therefore, if something changes in the environment, the development of agriculture, mining, and forestry brings a chain reaction, and the salamander will directly "collapse".
Today, in addition to a dozen protected areas in China (it is particularly worth mentioning that it has been found that a purely genetic wild population has been maintained in the protected area of Jiangxi Province), the giant salamander is almost extinct in the wild.
But there is no need to worry about the extinction of this species – they have been "luckily" bred on a large scale in many places (such as Shaanxi Province) – and can be regarded as a delicacy, traditional Chinese medicine, and a different kind of success in terms of genetic continuity.
Author thanks for your attention (- _-)