Cynops orphicus Risch, 1983
It is a rare species that appears to be in decline. Its habitat is probably being impacted by tourist development. Cynops orphicus is listed as endangered (IUCN, 2010). The locality may be isolated and have lost fauna diversity by clear-cutting (Gressitt, 1937).
Medium-sized Cynops distinguished from all other known species by the following combination of characters: Head flattened, with a fairly prominent canthus rostralis; skin very finely granulated; tail with small blackish dots and moderate dorsal and ventral fins; bright spots constantly present near base and palm on the underside of each fore and hind limb; ventral pattern consisting of an irregular light median longitudinal stripe and dark spots arranged in lateral rows (Risch, 1983). Closely related to but distinguished from C. orientalis by presence of conspicuous vertebral ridge and a bright ventral longitudinal stripe (Fei et al., 2006).
The mitochondrial genome has been sequenced by Zhang et al. (2008).
Medium-sized Cynops. Paratoids poorly developed. Dorsal surface of head smooth, flat, slightly concave, with a posteriorly pointing, slightly raised V behind middle, its apex joining vertebral line, which is slightly concave, becoming raised before base of tail. Limbs are small, fore limbs a little longer and only half as thick as hind limbs. Tail nearly as long as head and body length, ending in an acute tip. Skin smooth; sides almost without wrinkles; about fourteen indistinct costal grooves discernible on upper parts. Gula and throat almost without longitudinal or transverse grooves. Sexual dimorphism is well developed. The male has a swollen cloaca, a well developed dorsal tail crest, and is smaller than the female. Color brown to blackish above, bright orange below. Four large irregular blotches on gula. Irregular median stripe on belly, with a row of irregular blotches on each side. A spot near base and palm on undersides of arms and legs. Cloacal lips orange, black posteriorly. Tail bright red-orange on basal three-fourths of ventral fin, entire apical half becoming pale orange-brown, more orange on both fins, dotted with black blotches (excerpted from description of Gressitt in Risch, 1983).
All measurements are from Wu et al. (2010).
Female (5 specimens). Total length: 87.1–94 mm; snout-vent length: 44.4–52.7 mm; head length: 12–13.6 mm; head width: 8.6–10.1 mm; forelimb length: 13.4–15.5 mm; hind-limb length: 13.9–15.8 mm.
Cynops orphicus, C. orientalis and C. fudingensis forms a species group that is distributed along the coastal line of southeastern China. They differ from the Yunnan-Guizhou Plateau species group (C. chenggongensis, C. cyanurus and C. wolterstorffi.) and the Japanese species group (C. pyrrhogaster and C. ensicauda) both morphologically and genetically (Zhao & Hu, 1988; Weisrock et al., 2006).
Until recently Cynops orphicus was only known from its type locality near Dayang, at an altitude of 640 m in northeastern Guangdong, where it was collected as long ago as 1936. In 2001 some specimens were collected from Tian Chi Lake, Chao’an County, some 160 km NE from the type locality at 1,325 m altitude, and brought back alive to the Institute of Biology in Chengdu and the Museum of Vertebrate Zoology, Berkeley. Recently, however, a population of C. orientalis from Mt Daiyun, Dehua, in central Fujian Province was reassigned to C. orphicus (Fei et al., 2006), and this taxonomic change was confirmed by molecular analysis (Weisrock et al., 2006). As a result, the documented range of C. orphicus expanded northward to more closely approach the southern limit of C. orientalis (Wu et al., 2010).
The habitat in Dayang was described as located in a cultivated mountain valley (elevation 640 m), encircled by partly wooded mountains. The specimens were probably caught in pools connected with a small stream in the valley (Risch, 1983). In Mt Daiyun, Dehua, Fujian, animals were found in swamps at elevations of 1,400–1,600 m (Fei et al., 2006). The swamps are about 1 m in depth and have dense aquatic plants. In water the newts prey on earthworms, crustaceans, mites, insects and their larvae (Gressitt in Risch, 1983).
The reproductive behavior was observed in the laboratory in Chengdu and resembles that of C. orientalis (Sparreboom & Faria, 1997; Xie Feng, Max Sparreboom, pers. observ.).