#Chinese giant salamander

[bethanythebogwitch]

Wet Beast Wednesday: giant salamanders

Everyone knows salamanders, right? The little lizard frogs that show up around ponds. Well what if I told you that not all salamanders are little. In fact, some species can get quite large, but none get bigger than the aptly-named giant salamanders. I'm not just talking about any big newt, I'm talking about the unique members of the family Cryptobranchidae.

(Image: a Chinese giant salamander. It is a large, lizard-shaped animal with brown skin and black blotches. Its limbs are short and its tail is flattened to look like a long fin. It has wrinkly folds of skin along the side. End ID)

There are three(ish) species of giant salamander in two genera: the Japanese and Chinese giant salamanders of the genus Andrias and the hellbender of genus Cryptobranchus. The name Cryptobranchidae means "hidden gills", which is appropriate as giant salamanders are unique in that they are the only salamanders who reaming fully aquatic as adults without retaining external gills into adulthood. All salamanders are aquatic as juveniles and have external gills and many groups have independently evolved to remain fully aquatic as adults. However, other species, from axolotls to olms, adapted by retaining their external gills as adults, a trait called neoteny. Giant salamanders have had to find another way, especially since a body as large as their needs quite a bit of oxygen. Their solution was to take a common amphibian trait and turn it up to 11. It is common among amphibians to be able to absorb dissolved oxygen in water through their skin. This is usually a supplement to either gills or lungs, but giant salamanders use it as their main means of respiration. The skin is thin and filled with small veins that can perform gas exchange with the water. Giant salamanders evolved very wrinkly skin flaps along ther sides to increase the amount of surface area available for gas exchange, allowing them to sustain themselves. They do require access to running water with a high oxygen content, as still or low-oxygen water doesn't provide enough oxygen to survive. They do have lungs, but use them more for buoyancy control than breathing.

(Image: a man holding/bear higging a giant salamander. The salamander is longer than his torso, not including the tail. end ID)

The Japanese and Chinese giant salamanders are very closely related to each other and rather similar in physiology and behavior. There's also not just one Chinese salamander. Genetic testing has reveals that what was once called Andrias davidianus is actually a species complex. This is when what was thought to be one species turns out to actually be a group of related species. There is some debate over whether the five identified populations of Chinese giant salamander should be classified as subspecies or their own species, though the latter interpretation seems to be the most popular. All the populations are very similar and can interbreed with each other, so I'll discuss them as a group. The largest of the group (and world's largest amphibian) is the South China giant salamander (Andrias sligoi) which can reach 1.8 m (5.9 ft) and 50 kg (110 lbs), but adults average 1.15 m (3.8 ft) and 25-30 kg (55-66 lbs). The Japanese giant salamander (Andrias japonicus) reaches a slightly smaller maximum size of 1.5 m (5 ft) and 25 kg (55 lbs), with most being smaller. The Chinese and Japanese giant salamanders are closely related enough that they can hybridize.

(Image: a Japanese giant salamander resting on mossy rocks underwater. Its body is light brown with darker blotches and the head is covered in nodules. End ID)

Because of how closely related the Japanese and Chinese salamanders are, their biology and behavior are quite similar. They are mostly a dark brown color, but can also be other tones of brown, reddish, or black. The eyes are lidless, small, and poorly-developed, giving the salamanders poor eyesight. Their primary sense comes from the lateral line, a line of hair cells that extends down the body and sense movement of the water. Using the lateral line, the salamanders can sense the movement of prey and threats in the water around them. They utilize suction feeding, slowly approaching prey, then rapidly opening the mouth to generate a vacuum and suck food into the mouth. The prey is then killed or incapacitated with a powerful bite. The esophagus is lined with powerful muscles and uses mucus as lubricant to allow the salamander to swallow large prey. The head and throat have nodules on them, the arrangement and number of which can be used to differentiate Chinese and Japanese salamanders. Both groups of salamander can secrete a strong-smelling, milky white substance to ward off predators. A low metabolism and generally low activity level allows the salamanders to last of up to a few years between meals. The Chinese salamanders can make vocalizations including barks, hisses, and sounds very similar to the crying of a human baby. The hellbender (Cryptobranchus alleganiensis) is smaller than it's Asian relatives, reaching a length of 30-74 cm (12-29 in) and up to 2.2 kg (5 lbs). They are usually brown or reddish-brown, but can also have a gray, yellowish, or black coloration. Hellbender biology and ecology is fairly similar to that of their relatives.

(Image: a hellbender underwater. It looks like the other two species, but is smaller, lighter brown, and has no nodules on the head. End ID)

Chinese and Japanese giant salamanders live in cool, clear streams and rivers in the Yangtze river basin (Chinese) and the islands of Honshou, Kyushu, and Shikoku (Japan). Hellbenders live in similar treams in the eastern United states, with one population (which may be a subspecies) living in the Ozarks region. As predators, their diets include worms, fish, crayfish, freshwater crabs, other amphibians, and small mammals. They are also cannibals and will opportunistically feed on smaller members of their own species. All species are territorial animals that will attempt to drive others out of their territory, though hellbenders are less territorial than the other species. Hellbenders prefer to live in cavities dug out under rocks, which helps them shelter from predators. Due to their low metabolisms, giant salamanders live much longer than most amphibians. Captive individuals have been recorded living for 60 years (Chinese), 52 years (Japanese), and 25 years (hellbender). All species are nocturnal.

(Image: a hellbender emerging from beneath a rock with a crayfish in its mouth. End ID)

Mating occurs seasonally, triggered by warmer water in the summer. During this period, males will search for ideal nesting sites, leaving their territories if necessary. An idea nesting site is sheltered beneath a rock. There are often fewer nesting sites than males, meaning only the largest and strongest males will be able to claim nests. Males then use courtship displays to woo females. Alternatively, male hellbenders will chase passing females into the nests and refuse to let them leave until they mate. Unlike most salamanders, giant salamanders practice external reproduction, where the female lays eggs and then the male fertilizes them. The male then guards the nest until the eggs hatch. During this period, he will keep the nest and eggs clean and use his tail to keep water moving over them. Males will eat eggs that are unfertilized, unhealthy, or show signs of infection. This helps keep the other eggs as healthy as possible. The offspring are born with external gills, which they will lose as they mature. It can take several years for the larvae to reach maturity.

(Image: a group of giant salamander larvae in captivity. They look like smaller versions of the adults, but with feathery gills emerging from each side of the neck. End ID)

Both hellbenders and Japanese giant salamanders are classified as vulnerable by the IUCN, while Chinese giant salamanders are critically endangered. Their primary threats are habitat loss as streams are dammed, dry up, or become polluted. Warming water temperatures also threaten them. Chinese giant salamanders have experienced a major drop in population since the 1950s. In addition to habitat loss, Chinese giant salamanders are also eaten by humans. While hunting wild specimens is now illegal in China, they are heavily impacted by poaching. The fine for poaching giant salamanders is pathetically small compared to the sale price for one of them, further encouraging poachers. Captive breeding and release programs have shown some success, but may have contributed to the spread of disease. In response to the rarity of the salamanders, a new farming industry has sprung up in, raising giant salamanders for food. The captive population of Chinese giant salamanders in farms vastly exceeds the estimated wild population. Chinese giant salamanders have also been introduced to Japan, where they have been hybridizing with the Japanese salamanders, a major hindrance to conservation efforts. Japanese giant salamanders have been legally protected since 1951. The origin of the name hellbender is unknown. Other names for hellbenders include the water dog, Allegheny alligator, grampus, snot otter, and (my personal favorite) lasagna lizard.

(Image: a holding pen in a Chinese giant salamander farm. Over a dozen salamanders are sitting in a shallow water enclosure stocked with bricks and small fish. End ID)

I will leave this post off with a weird fact. In 1726, a Swiss physician named Johann Jakob Schuechzer declared a fossil giant salamander to be the remains of an ancient human who died in the mythical flood of Noah's ark and named it Homo diluvi, meaning "man who witnessed the deluge". In 1812, paleontologist Georges Cuvier examined the fossil and realized (probably very quickly) that it definitely wasn't a human. Once the fossil was identified as a salamander it was given the name Andrias scheuchzeri. As Andrias means "image of man", both the genus and species names acknowledge Schuechzer's weird idea.

Behold: a man (Image: the original Andrias scheuchzeri fossil that Schuechzer thought as a human. It is a front half of the skeleton of what is clearly a lizard-shaped animal and not a human. End ID)

[bjekkergauken]

Yangtze spirits

[trans-opossum]

Amphibiuary day 16: Swim!

[wuzhere75]

Chinese giant salamander. Scan ended up really blown out for some reason so I had to adjust a lot of stuff in procreate. Also my Posca pen has died or is broken in some way so I had to add a lot of white highlights digitally

[molekel]

Amphibiuary Day 16: Giant

A giant salamander, just walking down the road 

[uncharismatic-fauna]

A Big Round of Applause for the Chinese Giant Salamander

The Chinese giant salamander (Andrias davidianus) is one of the largest amphibians in the world, second only to the South China giant salamander (Andrias sligoi) which was only recently distinguished as a separate species. This species typically weights 25–30 kg (55–66 lb) and is 1.15 m (3.8 ft) in length, although It can reach up to 50 kg (110 lb) and 1.8 m (5.9 ft). Its anatomy is well-suited to its aquatic lifestyle; the broad, flat body allows it to creep along riverbeds, and its wide mouth allows it to gulp down any prey it might come accross. Their eyesight is very poor and as a result the eyes themselves are small. A. davidianus‘s skin is typically dark to blend in with its surrounding, and the excess wrinkles provide more surface area through which it can absorb oxygen from the water.

As their name suggests, the Chinese giant salamander is found only in China; specifically fragmented areas from Qinghai to Jiangsu and south to Sichuan, Guangxi and Guangdong. This species is entirely aquatic, and thus is most often found in the basins of the Yangtze, Yellow and Pearl Rivers. A. davidianus lives in caves or freshwater crevices, although they are also seen along lakes or open rocky riverbeds.

Part of the reason this species is so large is because they grow throughout their entire lives. Chinese giant salamanders start out as eggs, which are hatched in groups of 400-500 laid in slow-moving underwater cavities. The eggs are quite large, at a maximum size of 14–16 mm (0.55–0.62 in) after they’re laid and habe absorbed water. They take 50-60 days to hatch, and larvae emerge already resembling their parents, albeit with external gills, and are already 3 cm (1.2 in) long. The young are independent, although they typically stay in the stream they were hatched in until they’re fully grown. The gills are lost at 3 years old, although sexual maturity isn’t reached until 5 to 6 years and a length of 40–50 cm (16–20 in).

Mating occurs between mating occurs between July and September, when the water temperature reaches 20 °C (68 °F). During this time, males push sand and gravel out of their dens to clean them-- a process that can take up to a week-- and ‘shower’ regularly by moving under fast-moving currents. Females are attracted to clean dens, and once she chooses a mate the pair engage in a number of courtship behaviors including knocking bellies, leaning side-to-side, and cohabitating. After the female lays her eggs, she leaves and the male guards the eggs until they hatch. Individuals as old as 60 have been recorded in the wild, although few individuals survive past the larval stage.

Chinese giant salamanders have few predators as adults. The most common are otters, red foxes, weasels and hog badgers, although juveniles can also fall prey to large fish or even adult salamanders. To deter predators, A. davidianus secretes a white acidic, sticky substance from its skin. For the most part this species is the apex predator of its ecosystem, and feeds on insects, smaller amphibians, crustaceans, fish, and the Chinese water shrew (Chimarrogale styani). Individuals detect their prey by a combination of detecting chemicals in the water and a series of nodes along the sides of their bodies that sense vibration. When prey is located, the salamander creates a vaccum with their mouths, sucking in water and their meal.

Conservation status: The Chinese giant salamander is considered Critically Endangered by the IUCN. Primary threats include habitat loss, disease, and over-harvesting for meat. National and international conservation programs and zoos are working to raise awareness, conserve habitat, and raise captive-bred salamanders for re-release in the wild.

Extra fun picture for Chinese New Year:

This picture is from a series of paintings by artist Frankie Huang, who depicts a number of Chinese words literally. In this piece, the Chinese giant salamander is shown as the literal translation of its name in China: Wawayu, or ‘Baby fish’. This name comes from the salamanders’ distinct vocalizations, which can often sound like crying babies.

Photos

Theodore Papenfuss

Egon Heiss

Ben Tapley

Frankie Huang (Instagram)

[ormspryde]

This was supposed to be yesterday's amphibian but I didn't finish him until just now. The prompt was 'dragon', so I drew a water dragon based on a Chinese dragon and a Chinese giant salamander.

[ID: A digital painting of a Chinese dragon/Chinese giant salamander hybrid swimming underwater. /ID]

[whitedogblog]

Chinese Giant Salamander, the world's largest amphibian

[kosmickasper]

Chinese Giant Salamanders are silly and fun.

@cozy-fish-crow and I were laughing about this last night, so I had to make it a thing xD. based off this YouTube video

[us-the-voices-and-more-voices-2]

btw happy fact, pandas aren't endangered anymore.

woo!!!!

now we can put more love and attention ON CHINESE GIANT SALAMANDERS PLEASE I NEED AN UPDATE.

you can't just drop the lore that "oh yeah DNA testing shows theres like 5+ different species lolzor" AND THEN DISAPPEAR FOR LIKE 3 YEARS. (link -> salamanders)

PLEASE I CARE TOO MUCH ABOUT THEM

they are so endangered man, please

[feralfennecfox]

i just learned chinese giant salamanders exist and um??? look at himb???

[hidansexwife]

giant salamanders are some of my favorite herps

[muttertalk]

I love round poopoo mudfish

[harrisonposting]

[souldotdog]

WIP, giant Salamander. lol

[aquariuminfobureau]

The very largest salamanders alive today belong to the Chinese giant salamanders, the Andrias davidianus species complex. Chinese giant salamanders vary in length and weight, according to their location in China, with southern populations or species growing larger than the nominate populations further north. Typically Chinese giant salamanders are around 115 centimeters long, or 45 inches, but southern individuals may reach 180 centimeters or 71 inches.

Other than their differences in average sizes, the physical differences between the Chinese species in this complex are minimal. The recognition of several species that were formerly A. davidianus is widely accepted, but it is based on genetic phylogeography, forcing the recognition of important barriers to historical gene flow. It's still not sure how many species exist in the species complex per this criterion

The A. davidianus species complex is distributed in eastern, central, and southern China. A very similar related species, A. japonicus, is indigenous to Japan. There are a number of other Chinese species described other than A. davidianus, but they are all very similar animals. It is thought that all Chinese giant salamanders are capable of producing fertile offspring together, and similarly when crossed with the Japanese species.

Indeed introduced Chinese salamanders in Japan have hybridized with the native salamanders there. It is geographical boundaries that maintain all these animals as genetically distinct, and it's still unknown how many species of Andrias there are in Asia. The holotype populations of A. davidianus is native to waters of the Yangtze River basin. Other commonly recognized species in this complex are native to the Guandong, Jiangxi and Anhui regions of China.

The habitat of Asian giant salamanders is circumneutral upland streams with forest cover. Within these streams they fo not travel far from crevices between rocks, and caves in the riverbank where they lurk. These salamanders are primarily nocturnal and have a limited sense of vision, mainly detecting prey by sensing nearby changes in the water pressure that are caused by living animals and other moving objects.

Today the genus Andrias are referred to as the Asian giant salamanders, because they are today restricted to China and Japan. In the geological past species of Andrias were present in North America and Europe as well. It seems that they disappear from the European fossil recordwhen the climate cooled, as the Earth entered the Quarternary ice age. The youngest Western Palaearctic Andrias fossils are from the late Pliocene of the Caucasus region.

The famous discovery of a meter long fossil Andrias sp. in Germany, during the early 18th century, was initially misidentified as a fossilized human child, and described as 'homo diluvi testis'. At that time, living Andrias were unknown to Europeans, and although the identity of the fossil was soon suggested to be a salamander, it was not at first identified with its Asian cousins.

The nearest living relatives of Asian giant salamanders, today, are the hellbenders, Cryptobranchs, which are similar animals present in the eastern states of the USA. Some people think that there might be an unknown species of similar salamander, in the Trinity Alps of California. It has akso been suggested, though it is unconvincing, that tazelwurm sightings from Europe refer to an extant European Andrias species.

Asian giant salamanders and hellbenders form a clade called the cryptobranchids. Cryptobranchids seem to appear in the Palaeocene epoch, and the presence of the hellbender in eastern North America is a mystery, presumably involving prehistoric land bridges. Both Andrias and Cryptobranchus are slow moving bottom walkers, and suction feeding ambush predators.

Their skin has a folded and baggy appearance, because this increases its respiratory surface area exposed to the water. Although adult cryptobranchids have paedomorphic traits, which is common in aquatic salamanders, they do not have the external gill structures retained by so many other paedomorphic salamanders.

Asian giant salamanders are the largest amphibians in the world, and no fossil salamanders are known to be larger than are Andrias sp. The largest fossil salamanders are from Miocene strata, and they were themselves a species of Andrias, A. matthewi, growing to 230 centimeters. Andrias subsequently became extinct in North America

Chinese giant salamanders from South China are the largest, but they are now regarded as a different species from the archetypal A. davidianus. It is unlikely that their captive care would be significantly different. Some prehistoric stem amphibians were much larger, up to about 5 or 6 meters long, but their physiologies would not have resembled those of frogs or salamanders.

Unlike frogs, salamander size is not affected by seasonality in either precipitation or temperature. Yet neither major clade of amphibians, despite their diversity of species, has achieved the great body sizes that sharks, fishes, reptiles, and mammals have attained. Salamanders and frogs are thought to be limited in size by their method of gas exchange, which is across their hides.

A. davidianus is a subtropical amphibian, its optimal growth occurs occuring in water with a temperature of 15 to 21 degrees centigrade. Their feeding behavior was inhibited by water temperature lower than 8 or higher than 25 degrees, so high temperatures ought to be avoided. At low temperatures the adult salamanders become temporarily inactive for the wintertime, when the rivers run cold. Thus this species is unsuitable for tropical tanks, but it's temperature range matches that of an unheated but inhabited house in a climate such as that of Great Britain.

A. davidianus does not actually demand the sort of very cool water temperatures some people mistakenly believe they do, but a high dissolved oxygen content is important to them. The flow of the water should be vigorous enough to be visible at the water surface. Allowing the water to cascade down from the filter is one way to increase its dissolved oxygen content. The water should also be clear and well filtered. Normally it is said that the wild streams where giant salamanders live, have a pH of 6 to 7. However the pH in sampled stream habitats may also be as high as 7.7.

Their natural habitat of Asian giant salamanders has large boulders and a substrate of gravel. Therefore this species is well suited to inhabit a mountain stream biotope tank. Unfortunately they are predators of other motile animals, and able to ingest quite large prey. I have never heard of this animal being displayed in a mixed exhibit, other than in the moats of zoo enclosures. Needless to say these salamanders grow too large for most home aquariums

Sometimes it is said that these salamanders will drown if the water surface is not low enough for them.. Though they do breathe atmospheric air, they capable capable of swimming to the water surface to breathe. When they are stressed in the wild, these salamanders are known to retreat into the deeper water, so their water level does not need to be shallow, as long as they might access air.

These salamanders are predators mainly of fish and arthropods, but also opportunistically consuming mammals, reptiles, and frogs. They can be fed using tongs, to supply them defrosted meaty items of appropriate origins. When they sense that food is located beside their heads, they have the ability to to turn their heads and strike rapidly.