Mud salamanders typically have a blunter snout than the red salamander. Like other amphibians, the Chinese giant salamander is ectothermic. The axolotl is also a relative of the tiger salamander. The largest living amphibian is the South China giant salamander ("Andrias sligoi"). A newt is a salamander in the subfamily Pleurodelinae. Endangered species, such as the eastern tiger salamander, inhabit wetlands surrounding the village. Vertebrates consume guano as well, including the bullhead catfish and larvae of the grotto salamander. The Chinese giant salamander is listed as a critically endangered species. Severe mortality of tiger salamander larvae sometimes occurs from recurring ranavirus infections. Several subspecies of the fire salamander are recognized. The Japanese giant salamander ("Andrias japonicus") is a species of salamander in the family Cryptobranchidae. There are about 655 living species of salamander. One-third of the known salamander species are found in North America. The female salamander often broods the eggs. The Great Smokies are home to one of the world's most diverse salamander populations.