Animal Wednesday #78

Today is time for a very strange looking animal which is unfortunately critically endangered - Chinese giant salamander.

Chinese giant salamander

It has a large head, small eyes, and dark, wrinkly skin. Its flat, broad head has a wide mouth, round, lidless eyes, and a line of paired tubercles that run around its head and throat. Its color is typically dark brown with a mottled or speckled pattern, but it can also be other brownish tones, dark reddish, or black. Albinos, which are white or orange, have been recorded. All species of giant salamanders produce a sticky, white skin secretion that repels predators.

The average adult salamander weighs 25–30 kg (55–66 lb) and is 1.15 m (3.8 ft) in length. It can reach up to 50 kg (110 lb) in weight and 1.8 m (5.9 ft) in length, making it the second-largest amphibian species, after the South China giant salamander. The longest recently documented Chinese giant salamander, kept at a farm in Zhangjiajie, was 1.8 m (5.9 ft) in 2007. At 59 kg (130 lb), both this individual, and a 1.4 m (4.6 ft) long, 52 kg (114 lb) individual found in a remote cave in Chongqing in December 2015, surpassed the species' typically reported maximum weight.

The giant salamander is known to vocalize, making barking, whining, hissing, or crying sounds. Some of these vocalizations bear a striking resemblance to the crying of a young human child, and as such, it is known in the Chinese language as the "infant fish" (娃娃鱼 / 鲵 - Wáwáyú/ ní).

The Chinese giant salamander has been recorded feeding on insects, millipedes, horsehair worms, amphibians (both frogs and salamanders), freshwater crabs, shrimp, fish (such as Saurogobio and Cobitis) and Asiatic water shrew. Presumably ingested by mistake, plant material and gravel have also been found in their stomachs. Cannibalism is frequent; in a study of 79 specimens from the Qinling–Dabashan range, the stomach content of five included remains of other Chinese giant salamanders and this made up 28% of the combined weight of all food items in the study. The most frequent items in the same study were freshwater crabs (found in 19 specimens), which made up 23% of the combined weight of all food items.

It has very poor eyesight, so it depends on special sensory nodes that run in a line on the body from head to tail. It is capable of sensing the slightest vibrations around it with the help of these nodes. Based on a captive study, most activity is from the earlier evening to the early night. Most individuals stop feeding at water temperatures above 20 °C (68 °F) and feeding ceases almost entirely at 28 °C (82 °F). Temperatures of 35 °C (95 °F) are lethal to Chinese giant salamanders.

The Chinese giant salamander is entirely aquatic and lives in rocky hill streams and lakes with clear water. It typically lives in dark muddy or rocky crevices along the banks. It is usually found in forested regions at altitudes of 100 to 1,500 m (300 to 4,900 ft), with most records between 300 and 800 m (1,000 and 2,600 ft). There is an isolated population at an altitude of 4,200 m (13,800 ft) in Qinghai (Tibetan Plateau), but its taxonomic position is uncertain and the site likely does not support giant salamanders anymore due to pollution.

The salamanders prefer to live in streams of small width (on average, 6.39 m or 21 ft across), quick flow, and little depth (on average, 1.07 m or 3 ft 6 in deep). Water temperature varies