Xenochrophis flavipunctatus ( Hallowell, 1861 )

Published, First, 2012, 3473, Zootaxa 3473, pp. 1-60 : 25-29

Xenochrophis flavipunctatus ( Hallowell, 1861)

Figs. 19–24

Amphiesma flavipunctatum Hallowell, 1861: 503 .—Type locality by virtue of neotype designation: “ Island of Hong Kong ”, People’s Republic of China.— Neotype. USNM 7387 .

Tropidonotus piscator ornatus Wall, 1907 .

Taxonomic comments. This species seems to be rather homogenous despite the presence of several colour phases that are not geographically correlated.

Identification. Body cylindrical; tail length moderate. Maximum recorded total length 991 mm, female from Zhejiang Province, China (SMNH 1844). Examined males considerably shorter than females (maximum length females / males 1.26), largest male total length 784 mm (MNHN 1970.0452). Tail 27.6–34.8 % of total length in males, 23.9–30.5% in females. Head distinct from neck; eye large, its diameter greater than distance between eye and edge of lip. Dorsal scales in 19–19–17 rows, rather weakly keeled anteriorly, more strongly keeled posteriorly. Vertebral scales not notably large. Ventral scales: 120–137 in males, 128–143 in females, unkeeled; subcaudals: 70–91 in males, 60–83 in females, all paired; anal plate divided. Head scalation includes 1 loreal, 1 preocular, 3–4 (in one case 2) postoculars, usually 2 anterior temporals (less commonly 1, rarely 3), and 2 (less commonly 3 or 1, rarely 4), posterior temporals, 9 (exceptionally 8 or 10) supralabials with 4 th to 5 th (sometimes only 4 th, in one case 5 th and 6 th on right side) contacting eye, 9–11 (usually 10) infralabials with anteriormost 5 (rarely 4 or 6) touching anterior chin shields.

Body above in different shades of olive, brown, dark grey or pale grey, with many more or less clear, dark dots arranged in 6–7 lines alternating to give chequered pattern. These dots clearer on anterior part of body; posterior part may be chequered or uniform. In dark specimens, these spots barely visible, in pale specimens spots very conspicuous. Series of more or less clear, dark dots present on flanks, mostly not reaching ventral scales. These dots paler than dorsal ones, sometimes visible when dorsal dots are not. Many specimens have pale margins on some (irregularly) rhombic dorsal scales, on one, two or three sides. Some specimens have vivid red or orange spots laterally ( Fig. 21) that vanish in preservative.

Head coloured as body; a conspicuous black bar running from eye to mouth, another from just behind eye to corner of mouth, space between these bars sometimes yellow. Upper lips paler than dorsal part of head, sometimes partly whitish-yellow or yellowish-grey. Conspicuous Y-shaped marking on neck, starting at corner of mouth and pointing posteriorly. Generally (149 of 168 specimens), club-like mark on occiput extending into nuchal mark to break it in its middle. Often (114 of 143 specimens) two darkly bordered pale ocellion parietals, sometimes difficult to see. Tail more or less uniform. Venter whitish-yellow with ventrals and subcaudals bordered in black (sometimes broken in paler specimens) on posterior margins.

Young specimens more colourful, bright blackish-brown above, seven rows of subequal alternate black spots with median row becoming obscure with age. Spots and dots on parietal region not yet differentiated, head dorsally uniformly black brown, extending backward onto nape. Pale postoccipital band contrasts more strongly with dark dorsum of head and back than in adult. Supralabials much darker. Ventral plates without black margins ( Fan, 1931; Pope, 1935; Tweedy, 1983; Ziegler, 2002; our data).

Distribution. This species is distributed throughout Southeast Asia. People’s Republic of China. South and southeast: provinces of Anhui, Fujian, Guizhou, Guangxi, Guangdong, Hainan, Hong Kong, Hunan, Jiangsu, Jiangxi, Yunnan, Zhejiang and Xizang (Tibet). Myanmar. South, centre and east. Thailand. Throughout the country. Vietnam. Throughout the country. Laos. Throughout the country. Cambodia. Throughout the country. Federation of Malaysia. Throughout West Malaysia. Singapore. This species also occurs in Taiwan ( Zhao & Adler, 1993; Zhao et al., 1998).

Discussion. Schmidt (1927) discussed the pholidosis of 110 Hainan specimens of Xenochrophis flavipunctatus under the name Natrix piscator . These data were copied by Pope (1935). The major counts are (our values for specimens from Hainan are listed in brackets): 122–133 (120–132) ventrals in males, 134–145 (128–143) ventrals in females. Subcaudals 73–88 (76–91) in males, 64–77 (62–83) in females. Largest male 668 mm (748 mm), female 975 mm (991 mm). Relative tail length 29–33 % (27.6–34.8) for males, 23–28 % (23.9–30.5) for females. These data fit well with our findings, considering that Schmidt did not count according to Dowling’s method and his ventral counts should be about two higher than ours.

Deuve (1963a, b) discussed the pholidosis of Laotian members of this genus in detail under the name Natrix piscator . According to his description, he had X. flavipunctatus at hand. It cannot be excluded that he also included specimens of X. piscator , because both species occur in northwestern Laos, for example near Vientiane. Not all of his data can be discussed here, because Deuve went more deeply into some character variation than is within the scope of this review. Only his major results are compared here. Deuve recorded 19 middorsal scale rows without exception, and this agrees with our findings. He counted 124–147 ventrals, (mean 135) but his data were not counted by Dowling’s method, so values might be about two higher than ours. Deuve’s counts are a little higher than ours for this species (120–143 for both sexes combined). Deuve’s other data (compared to ours, inparentheses) are 69–90 (62-91) subcaudals, mean 79; relative tail length 0.25–0.34 (0.24–0.35); maximum length 960 mm for a specimen with mutilated tail (991 mm). Considering the fact that all Deuve’s specimens originated from Laos, it is quite surprising that these data correspond so closely, indicating that there is extremely little geographical structure to the variation in this species.

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Taylor (1965: 838) gave a table with some scale counts of X. piscator and X. flavipunctatus from northern Thailand. In this table, the variation for the ventrals of his females is 135–144 (our data for the whole distribution 128–143), for his males 125–131 (our data 120–132). Taylor did not use Dowling’s method. For the subcaudals Taylor gives 72–77 (our data 62–83) for females and 82–84 (our data 76–91) for the two complete males he had at hand. The relative tail length is 0.24–0.28 in his females (0.24–0.31) and 0.29–0.30 in his 2 males (0.28–0.35). All of these data very closely agree with our findings. In the text, Taylor (1965) gave a maximum length of 1200 mm for this species, followed by “see table”. According to the table, the maximum length for X. flavipunctatus is 765 mm, which agrees well with our data. We assume that Taylor made a mistake in his text, or, more likely, took the maximum length from the literature, in which case this value may refer to X. piscator .

Zug et al. (2006) discussed populations of X. flavipunctatus from Myanmar and also came to the conclusion that this taxon justifies a species rank. They compared four specimens from Myanmar and three from Hong Kong with 20 X. piscator from Myanmar. Their values agree with our results, with the exception of the subcaudals of the three males from Hong Kong, for which the authors gave a variation of 60–80. This is quite high for a variation in one population, counted from three specimens of the same sex (making a standard deviation of 14.1). Because our lowest counted value for subcaudals in males of this species is 62 (n = 80) we believe the value of 60 resulted from some kind of error .

Material examined (233 specimens). Myanmar. Ayeyarwady Division. USNM 562756–59 , Moyingye Wetland Bird Sanctuary, about 80 km northwest of Yangon.— People’s Republic of China . Fujian Province. CIB 64 II5371, CIB 64 II5376, CIB 64 II5426, CIB 64 II5543, CIB 64 II5583, Daiyun , Dehua County; SMNH 1317–19 , no locality; SMNH 1325–33 , no locality; SMNH 1334 , Guadun. Guangxi Province. MNHN 1902.0069 , “Lungchow”, now Longzhou ; MNHN 8776 , no locality; SMNH 1323 , no locality. Guangdong Province. SMNH 2090–92 , Guangzhou ; SMNH 2095 , SMNH 2099–2103 , SMNH 2421 , SMNH 2093–94 , SMNH 2098 , no locality; ZMH R07933 , “Canton”, now Guangzhou. Guizhou Province. CIB 63 III5040, CIB 63 III5081, Bajie , Xingyi County, 650 m; CIB 63 III5093, Xintian, Bajie , Xingyi County, 650 m; CIB63 III 5328, Zhouanhe, Bajie , Xingyi County, 690 m; CIB 63 III6028, CIB 63 III6036, CIB 63 III6046, Luoyang , Luodian County, 370 m; CIB 63 III6059– 60, Luoyang , Luodian County, 340 m. Hainan Island and Province. CIB 639026 , no locality; CIB 64 III5642– 43, CIB 64 III6008, CIB 64 III6062–63, Dali, Diaoluo Shan ; CIB 64 III6264–65, CIB 64 III6267–69, CIB 64 III6271, Nanxi, Diaoluo Shan ; FMNH 6728–32 , no locality; SMNH 659 , SMNH 1320–22 , SMNH 1324 , Haikou City; SMNH 2449 , Luopeng ; SMNH 3015–16 , no locality; SMNH 2464 , Jianfenglin ; SMNH 4487–90 , no locality. Hunan Province. CIB 75 I5007, Dongfeng, Mangshan , Yizhang County, 480 m; CIB 75 I5012, Dongfeng, Mangshan , Yizhang County, 500 m; CIB 75 I5208, Mangshan , Yizhang County; CIB 75 I5367, Gongshe, Chengnan, Yizhang County . Yunnan Province. FMNH 24815 , Yuan Kiang, now Yuanjiang ; SMNH 3017–3019 , SMNH 3021 , SMNH 3022–3027 , Mengyang, Jinghong County . Zhejiang Province. SMNH 58 , Taiping ; SMNH 1835–1847 , SMNH 2528 , Longquan ; SMNH 1848 , Taisun ; SMNH 3531 , Ningbo.— Thailand. Chanthaburi Province. BMNH 1987.1736 , Chanthaburi. Chiang Mai Province. BMNH 1977.1931 – 2 , ca. 30–32 km Southwest of Chiang Mai; FMNH 142159 , FMNH 169411 , FMNH 169413 , FMNH 178627–33 , Chiang Mai. Chiang Rai Province. MNHN 1998.8536 , Chiang Rai City. Kanchanaburi Province. FMNH 178705 , no locality. Lampang Province. BMNH 1987.1733 , Lampang. Prachuap Khirikhan Province. PSGV 577 , no locality. Nakhon Ratchasima Province. FMNH 180161 , FMNH 180163–64 , FMNH 180185–87 , Amphu Pak Thong Chai, Sakaerat. Nakhon Si Thammarat Province. FMNH 191104–05 , Songkhla. Phang-Nga Province. MNHN 1999.7614 , Ban Tha Dan, Muang District . Phuket Island. BMNH 1977.1925 , Phuket City. Tak Province. BMNH 1977.1933 , on a road between Sukhotai and Tak, 26 km East of Tak. Ubon Ratchathani Province. FMNH 178644–45 , Ubon. Uthai Thani Province. ZMH R05306 , no locality. Other locality. MNHN 1885.0395 – 96 , between Bangkok and Chanthaburi.— Laos . Bolikhamxay Province. FMNH 254785–86 , no locality. Champasak Province. FMNH 255241–42 , village on Mekong River, 14°22'N, 105°52'E, 60 m, Dong Khantung NBCA, Mounlapamok District ; MNHN 2003.3345 , Kiatngong, Xepian NBCA, Bolovens. Khammouan Province. FMNH 255243–45 , Nakai District . Savannakhet Province. MNHN 1963.0756 , MNHN 1963.0760 , no locality. Vientiane Prefecture. MNHN 1962.0288 , Vientiane; MNHN 1962.0290 , bank of Mekong, Vientiane; MNHN 1962.0291 , Thangon, 24.5 km north of Vientiane; MNHN 1963.0753 , bank of Mekong, 5 km north of Vientiane; MNHN 1963.0757 , Thangon, 25 km north of Vientiane; MNHN 1963.0759 , on the bank of Mekong, 10 km from Vientiane; MNHN 1963.0754 , garden in Vientiane; MNHN 1963.0755 , garden of Vientiane Hospital ; MNHN 1963.0758 , in a rice paddy, 6 km north of Vientiane; MNHN 1963.0761 , Sikhang, 5 km from Vientiane; MNHN 1985.0403 , near Vientiane. No locality. ZMH R05308 , 100km W of Vientiane .— Cambodia. Koh Song Province. MNHN 1970.0449 , Kirirom. Kompong Chhnang Province. MNHN 1970.0454 – 59 , Trapeang-Chan. Phnom Penh Province. MNHN 1963.0716 – 19 , Phnom Penh. Siem Reab Province. MNHN 1970.0450 – 53 , Angkor. No locality. MNHN 1988.2103 , “Cambodge”.— Taiwan. ZMB 8491 , Tamsui.— Vietnam. BMNH 1920.1.20.453(1–2),“ Saigon ”, now Ho Chi Minh City. CAS 105028, 2.5 mi. NW Hoa Phat. Quang Nam Province; MNHN 1885.0302 , “ Vietnam ”; MNHN 1885.0293 – 0300 , MNHN 1885.0397 – 0399 , “Ba Chien”, now Bà Chin, Lam Dong Province; MNHN 1894.0108 , “Annam”, now Central Vietnam ; MNHN 1907.0032 , Hai Duong, Hai Duong Province; MNHN 1911.0007 , MNHN 1908.0193 , MNHN 1911.0113 , MNHN 1912.0064 , MNHN 1974.1355 – 57 , “Tonkin”, now Northern Vietnam ; MNHN 1908.0038 , “ Poste de Baria , Cocinchine”, now Bà Ria, Bà-Ria - Vũng Tàu Province; MNHN 1908.0053 (1–3) , “Cocinchine”, now Southern Vietnam ; MNHN 1911.0032 , “ Tonkin, Pointe Pagode ”, now a cape at 21.28N 107.45°E near Tiên Yên , Quang Ninh Province; MNHN 1916.0019 , MNHN 1928.0032 , “ Indochine ”; MNHN 1927.0059 – 60 , “ Annam ( Indo-Chine )”; MNHN 1974.1279 , MNHN 1974.1284 , “ Region de Saigon ”, vicinity of Ho Chi Minh City; MNHN 1974.1281 , “Arboretum de Trang Bôm”, now ”, now the Arboretum of Bien Hoa , Dong Nai Province; MNHN 1991.1610 , “Tonkin, Tien Yen”, now Tiên Yên, Quang Ninh Province; PSGV 394.1 – 6 , PSGV 533 , Tam Dao, Vinh Phuc Province.— West-Malaysia : BMNH 1965.974 – 78 , Alor Star, State of Kedah. BMNH 95.10 . 7.8, ZMH R07943 , Penang Island ; BMNH 97.2 . 3.4, Penang Hill, Pulau Pinang.— No locality. MNHN 1989.205 , Southeast Asia , MNHN 1891.236 – 237 , Nias Island , Indonesia, locality doubtful .