Chinhai Spiny Crocodile Newt

Echinotriton chinhaiensis is a stout salamander with flattened body and head, and with a series of ca 12 conspicuous knob-like, porous lateral glands. The head is broad and triangular in shape. It is uniformly dark brown or black on the dorsal and ventral sides, with only the underside of the tail, cloacal region, and the soles of the feet coloured yellow-orange. The skin is granular. Vomero-palatine teeth in V-shape, arranged in two longitudinal series, meeting in front. Total length is approximately 120 mm in males and 140 mm in females, the tail is usually shorter than the snout-vent length (Chang 1932; 1936; Cai and Fei 1984; Ye et al. 1993). There is no obvious morphological distinction between the sexes. In both sexes the cloacal opening consists of a longitudinal slit. When slightly opened, the cloaca of the female is smooth on the inside, whereas that of the male is more rugose. When carrying eggs, females have distended abdomens. In the male the vent is swollen during the mating season. Genetic diversity within the only known population is low, but not significantly (Xie 1999). The genus Echinotriton comprises two species, E. chinhaiensis, occurring in Zhejiang in China (Cai and Fei 1984) and E. andersoni, endemic on five islands of the Ryukyu archipelago, Japan (Nussbaum and Brodie Jr. 1982, Nussbaum et al. 1995, and Zhao and Adler 1993 refer to a find of E. andersoni on Taiwan, but the species’ occurrence there has not been confirmed). Echinotriton is unique among amphibian genera in having an anteriorly curved spine on the posterolateral surface of each quadrate. Echinotriton is most similar to Tylototriton, but differs in a number of significant morphological and life history features. The ribs of Echinotriton are free of muscular attachment distally, sharp-tipped, and often penetrate the skin through the primary warts. Echinotriton has a stockier body than Tylototriton, with shorter limbs, digits and tail (Nussbaum and Brodie Jr. 1982). The adults are completely terrestrial and deposit their eggs on land, whereas the larvae develop in lentic water bodies. E. chinhaiensis is closely related and very similar to the Japanese sister species E. andersoni (Zhao and Hu 1988), but differs from that species in that it lacks the rows of secondary warts running on each side of the vertebral crest, between vertebral column and the row of primary warts, supported by the ribs. It has only one epipleural process on each of the ribs 2 to 4; the fifth toe is normally developed; it has 5 metatarsals and 9 tarsals (Cai and Fei 1984).During a 1999 vertebrate survey in Zhejiang, one more locality was discovered in Qiushan valley; two female salamanders were found at the edge of a small puddle, entirely covered with terrestrial vegetation. The species has not been reported from the terra typica (Chengwan) for many years and could not be found during the survey of April 1999. It must be considered extremely rare.

E. chinhaiensis is known only from the type locality and two nearby valleys east of the city of Ningbo (respectively Chengwan, Ruiyansi and Qiushan, district of Beilun, province of Zhejiang, China), where it inhabits a forest area 100-200 m above sea level. Over the last 20 years, the species has been reported only incidentally from the type locality. The typical spawning habitats around the ponds to which the females migrate are characterized by a combination of features: There is dense plant cover around the ponds. The vegetation is composed of an upper layer of evergreen broad-leaved trees, a middle layer of shrubs, and a lower layer of grasses, creating a dark and humid habitat. The ponds are semi-permanent with a pH value of 6 to 7. The water bodies are small and shallow, receiving water mainly from rain. The egg-laying areas consist of slopes and flat ground directly bordering the ponds; the surface consists of loose soil and stones and is invariably covered by a thick leaf litter (Xie et al. 2000).

The female lays 72 to 94 large, single eggs on land, in one or several clutches (Cai and Fei 1984). Communal nesting sites may contain several superimposed layers of eggs (Xie et al. 2000). Eggs are laid in the humus or under rotting leaves in places close to ponds, puddles and springs. The breeding season extends from late March to late April (Xie et al. 2000). Both migration to oviposition site and hatching of the larvae appear to be related to rain-fall. The egg capsule measures from 7.2 to 10.5 mm in diameter and consists of three layers; the egg proper is 3.2 to 3.8 mm in diameter. It is light yellow, lacking brown pigments (Cai and Fei 1984). The female does not attend to the eggs and moves out of the breeding site immediately after egg-laying. After about three to four weeks, in May, the larvae are flushed out of the terrestrial oviposition sites by rains and are capable of finding their way to water by wriggling over land and leaping to some cm above the ground (Xie 1999; Xie et al. 2000). Balancers may be observed 4 to 5 days after oviposition; these are resorbed some five days later. Larvae are without balancers at the time of hatching and measure approx. 20 mm. From egg to metamorphosis takes ca 110 days. Newly metamorphosed salamanders with a total length of 34 to 40 mm climb on land in August (Cai and Fei 1984; Xie 1999). The population in Ruiyansi Forest Park probably consists of no more than ca 370 adult animals (Xie 1999). Both males and females of this salamander lead a largely hidden terrestrial life and are difficult to observe outside the breeding season. They are inactive during the day and very slow moving when active. Hibernation takes place from November to March. In the reproductive season, only the females move to the oviposition sites. Males are rarely found. Mating takes place on land and has only been observed in the laboratory (Sparreboom and Xie 1999-2000, unpubl. obs.). The male approaches the female and deposits several spermatophores on land. The couple makes a circular movement, in the course of which the female is led over the spermatophore. Food consists of earthworms, snails and Scolopendridae (Cai and Fei 1984). E. chinhaiensis exhibits a stereotyped rigid antipredator posture (the unken reflex) during which the body is flattened and curled up and the hands and tail are raised. The species has elongated, sharp ribs with sharp epipleural processes, capable of piercing through the lateral warts (Cai and Fei 1984).

The one population that has been followed over the years is in Ruiyansi Forest Park, near the city of Ningbo in the province of Zhejiang. Suitable habitats featuring a combination of characteristics such as sufficient cover for the eggs and appropriate water bodies for the development of larvae, are rare. Road construction and deforestation contribute to fragmentation of the scarce habitats and to a decrease in populations and number of individuals; pollution of the breeding habitat is a serious threat (Xie et al. 2000). Cai and Fei (1984) and Fei (1992) signaled that the habitat in the valley was rapidly decreasing, giving way to cultivation of tea plantations, orange orchards and other small scale agriculture. The one population that was known, that of Ruiyansi, looked still relatively healthy but was isolated and vulnerable, and had to be considered endangered. As a consequence, in 1988 E. chinhaiensis was listed in the grade 2 category of major state protected wildlife (Zhao 1998), which implies that since that time the capture and handling of this salamander were licensed by the state government.

Generally the animal is not noticed by local inhabitants, except incidentally during digging up bamboo sprouts. In 1999, artificial ponds were created near the known breeding ponds in Ruiyansi Forest Park. Attempts are being made to prevent farmers from dumping pollutants and cleaning their equipment in the ponds. The species has been captive-bred on a small scale in an outdoors enclosure at the Chengdu Institute of Biology.

The Chinhai spiny newt (Echinotriton chinhaiensis) is a species of salamander in the family Salamandridae, found only in a small section of Zhejiang province in eastern China. Its natural habitats are temperate forests, freshwater marshes, and ponds.

The Chinhai spiny newt is unique to the Beilun District east of Ningbo. It is threatened by habitat loss.

Observations of captive animals suggest the Chinhai spiny newt is a late-maturing, long-lived species: they reach sexual maturity at 10 years age or later, and their lifespans are at least 20 years.