Paramesotriton fuzhongensis Wen, 1989
Listed as Vulnerable (IUCN, 2010). Fewer than ten locations are known. There is a decline in extent and quality of its habitat and in the number of mature animals found.
A large and stout newt, the skin densely covered with warts. Similar to P. chinensis but larger and covered with more and larger warts, and no black tail end in the female (Thorn & Raffaelli, 2001). Similar to P. guanxiensis but with a more warty skin, longer and narrower head, longer and lower tail, and possession of black mottling on the back in many individuals, which is rare in P. guanxiensis. Fore limbs of P. fuzhongensis reaching between the eye and nostril when drawn forward, while those of P. guanxiensis do not reach as far (Wen, 1989).
The mitochondrial DNA sequence data are available from Weisrock et al. (2006) and Wu et al. (2010).
Large, robust newt with very warty skin. Head longer than wide. Upper labial fold prominent and more developed under eyes. Fore and hind limbs of nearly equal length, with hind limbs stouter and tip of fore limb reaching midway between nostril and eye. Adpressed fore and hind limbs overlap. Toes with blunt, round tips. Tail shorter than snout-vent length, thick at the base and gradually becoming laterally compressed. Skin very rough with prominent dorsal ridge. Entire body, from head to anterior part of tail and dorsal surface of limbs covered with warts. Large dorso-lateral warts form two ridges. Underside from labial fold to belly, and fore and hind limbs are smooth. Color of backside dark to olive-brown, occasionally mixed with a lighter or darker color. Sometimes small dark spots on back. A light vertebral stripe in some specimens. Belly pattern consisting of large, disconnected orange or red blotches extending onto throat and chin. Male smaller than female, with a shorter and higher tail. Orange spots on throat smaller than in female. During the breeding season, tail of males may have grayish-white stripes or various black spots.
All measurements are from Wen (1989). The largest female kept by Sparreboom (1991) measured 21 cm.
Male (4 specimens). Snout-vent length: 75–88 mm; tail length: 58–78 mm; head length: 23–27 mm; head width: 16–20 mm; forelimb length: 25–29 mm; hind-limb length: 25–30 mm.
Female (3 specimens). Snout-vent length: 69–80 mm; tail length: 65–79 mm; head length: 21–34 mm; head width: 14–16 mm; forelimb length: 20–26 mm; hind-limb length: 22–27 mm.
Paramesotriton fuzhongensis is not unanimously recognized as a separate species. Pang et al. (1992) suggested that P. fuzhongensis is very similar to P. chinensis based on morphology, osteology and morphometric measurements, except that P. fuzhongensis is larger and has higher caudal fins. However, molecular phylogenetic analyses indicate a close relationship between P. fuzhongensis and P. guangxiensis and P. yunwuensis (Weisrock et al.,2006; Wu et al., 2010). Furthermore, the LDH isozyme patterns on polyacrylamide gel electrophoresis show a difference between P. fuzhongensis and P. guangxiensis, confirming the species status of P. fuzhongensis (Yuan et al., 2000).
This species is only known from northeastern Guangxi (Zhongshan, Fuchuan and Gongchen Counties) in China, where it lives at altitudes from 400 to 1,200 m (IUCN, 2010).
The newt inhabits montane streams surrounded by broad-leaf forests. It prefers the pools under the waterfalls (Wu, Y. pers. comm.). Adult animals may be found under rocks and sometimes on land. Reproduction takes place in the streams (Wen, 1989).
Reproductive behavior was observed in captivity in February and March. Courtship patterns have been described in part, and for animals labeled P. chinensis, but in fact probably belonging to the form described later as P. fuzhongensis (Sparreboom, 1984abc, 1991). Aquarium observations have shown that the male defends a territory, normally near a hiding place or at a spot where he can oversee his surroundings. He approaches and attacks intruding newts - males and occasionally also females. When the intruding animal flees, the resident male returns to his spot. If the attacker bites, for instance in a leg or tail, he may hold on during several minutes and make jerking movements with his head. A bitten animal assumes a characteristic position. It curls up sidewards around the head and neck of the attacker, eyes closed, and remains motionless, until the attacker loosens its grip and lets go. Both males and females are subject to attacks, and females may also be aggressive. This aggression probably serves to maintain a kind of territory, and could be interpreted as a mechanism to monopolize suitable mating places on the bottom of streams. Courtship takes place at night and follows the stages described for P. hongkongensis (Romer, 1951; Arnold, 1972) and P. deloustali (Rehák, 1984). The male is standing on the alert with his fore legs stretched and his head raised a little. He approaches a female, and after he has identified her as such, starts fanning his tail, creating a stream of water directed toward her snout. A responsive female keeps standing still. At a certain moment the male turns round and walks ahead a few paces. The female orients herself towards the silver stripe in the tail of the male and touches it with her snout. The male creeps on and deposits a spermatophore on the substrate; the female follows the male, moves over the spermatophore and, if all goes well, picks up the spermcap with her cloaca. The male may deposit several spermatophores in one sequence (Sparreboom, 1991).
Egg deposition was observed in captivity, from March to May. Eggs are large, the jelly mass measuring 5 to 6 mm, the egg diameter 2,5 to 3 mm. Eggs are laid between leaves; leaves are not folded around the egg as is seen in Cynops. Larvae hatch after three to five weeks, depending on water temperature, and in different stages of development, measuring 10 to 12 mm. Larvae are black or dark brown, some may have cream colored dots on back and belly, gills reddish, iris white and a white spot on the snout. At metamorphosis they measure approximately 40 mm (Sparreboom, 1984c). Juvenile newts are dark brown, sometimes with orange dots and stripes on the back (Thorn & Raffaelli, 2001; Miller, 2005).