Xenochrophis melanzostus ( Gravenhorst, 1807 )

Published, First, 2012, 3473, Zootaxa 3473, pp. 1-60 : 34-37

Xenochrophis melanzostus ( Gravenhorst, 1807)

Figs. 29–30

Coluber melanzostus Gravenhorst, 1807: 402 .—Type locality by virtue of neotype designation: “Batavia, Java ”, now Jakarta, Java Island , Indonesia.— Neotype, by present designation: MNHN 0060 .

Coluber lippus Reuss, 1834 .

Taxonomic comments. This species has long been regarded as a subspecies of X. piscator in the literature (e.g., Smith 1943). David & Vogel (1996) suggested a close relationship between the taxa melanzostus and X. flavipunctatus . Das (1996) considered X. melanzostus a valid species. According to our data, there is little doubt about the distinct specific status of this form. It is morphologically more similar to X. flavipunctatus than to X. piscator . Xenochrophis melanzostus is probably endemic to Java and Bali, it being only recently reported from Bali ( Kusuma et al. 2010). Records for Sulawesi and Borneo are erroneous ( Stuebing & Inger 1999; Lang & Vogel 2005). Its occurrence in Sumatra is here confirmed (see below). The population from the Andaman Islands is here referred to a different species, X. tytleri (see above).

Identification. Body cylindrical, stout; tail length average for this group. Maximum recorded total length 1,200 mm ( Bergman 1958); largest specimen seen by us 1,079 mm long (female; IRSNB 325). Examined males considerably shorter than females (maximum length females / males 1.62), largest male total length: 665 mm (MNHN 5594). Tail 28.6–30.2 % of total length in males, 23.3–26.5 % in females. Head distinct from neck, eye average, its diameter about as great as distance between edge of upper lip and lower margin of eye. Dorsal scales in 19–19–17 rows, distinctly keeled except outer two or three rows; vertebral scales not enlarged. Ventral scales 128– 134 in males and 136–143 in females, unkeeled; subcaudals 78–83 in 7 males and 66–77 in 14 females, unkeeled and paired; anal plate divided. Head scalation includes 1 loreal, 1 preocular, 3 (in one case 2) postoculars, 2 (in one case 1) anterior temporals, and 2 or 3 posterior temporals, 9 supralabials (rarely 10) with 4 th to 5 th (rarely the 4 th in one case the 5 th and 6 th) contacting eye, 10 (rarely 9 or 11) infralabials with anteriormost 5 (in two cases 6) touching anterior chin shields.

Yellowish-brown, grey or olive-brown above. There are two morphs, blotched and striped respectively. Blotched morph with 4 rows of large black blotches on neck and vertebral row of blotches starting behind neck. Striped morph with 4 dark brown or black stripes on neck, quickly turning to 5 stripes on body due to addition of pale centred, dark brown or black edged vertebral stripe. In both forms marks might vanish on posterior part of body or turn into spots. Both morphs might have dark margins on some dorsal scales. Margins may occur irregularly on one, two or three of scale sides, on some but not all scales in the same way as in X. flavipuncatus . According to Hodges (1993) both morphs equally common. Both morphs may also have bright red flanks (see Fig. 27–28). These different patterns and colours make this species extremely variable.

Head olive grey or yellowish grey, darker than body; one dark brown or black streak below eye, another, oblique one starts behind eye; sometimes small black edged spots or a pale bar on parietals; large, dark vertical crossbar on each side of neck behind posterior end of upper jaw; marks are forming a widely open “V” when seen from above.

Venter yellow, yellowish-grey or cream, ventrals often edged with black. Chin and throat yellowish-cream. Subcaudals may also have black crossbars at their origin ( Gravenhorst 1807; de Rooij 1917; our data).

Distribution. Indonesia. This species is widespread in Java and has recently been recorded from Bali ( Kusuma et al. 2010). This species is also present in Sumatra although, by all evidence, it is rare or at best localized in this island. Only two precise localities have been recorded in the literature: vicinity of Bengkulu, Bengkulu Province ( Kopstein 1935) and Palembang, Sumatera Selatan Province (de Rooij 1917). These records are supported by voucher specimens, although not seen by us. We here add a third locality, based on NMW 22334, stated to come from “Deli”, now Medan, Sumatera Utara Province. On the basis of these specimens, we consider that this species is indeed present in Sumatra. We also examined another specimen, ZMB 30853, from Sumatra without precise locality data.

Discussion. Bergman (1958) found differences in the counts of ventrals and subcaudals between specimens from the plains and those from the hills of Java. For ventrals he gave 131–138 for males, 141–152 for females in the plains, and 127–135 for males, 140–146 for females in the hills. For subcaudals he gave 74–82 for males, 65– 73 for females in the plains, 78–86 for males, 67–80 for females in the hills. Bergman measured 126 specimens, recording a maximum length for females of 1,200 mm and for males of 835 mm (maximum length females / maximum length males 1.44). Bergman included data of Kopstein (1941); see Table 3.

Material examined (28 specimens). Indonesia. Java Island. BMNH 44.4 . 13.7, “ Borneo Ceram ” (in error?); BMNH 49.1 . 12.8, BMNH 94.3 . 24.10, “ Java ”, no locality; BMNH 1935.11 . 9.1, “ Magdang , Java ”, now Magelang , Jawa Tengah (Central Java) Province. IRSNB 306 , IRSNB 325 β, “ Batavia ”, now Jakarta; IRSNB 306 Ύ, IRSNB 306 Ύ2, IRSNB 307 β, “ Java ”, no locality. MNHN 0060 (neotype), “Batavia”, now Jakarta; MNHN 7410 , MNHN 1911.0163 , MNHN 1991.1600 – 06 , MNHN 3517 , “ Java ”, no locality; MNHN 5594 , Celebes (in error?). Sumatra Island. NMW 22334 , “ Deli , Sumatra ”, now Medan, ZMB 30853 , Sumatra. “ Ambon ”, in error (?). IRSNB 307 C, IRSNB 307 Ɛ (specimen 1–2), IRSNB 3079 , IRSNB 325 , “ Ambon ” .