Aipysurus eydouxii ( Gray, 1849 )

Sanders, Kate L., Rasmussen, Arne R., Elmberg, Johan, Guinea, Michael, Blias, Peter, Lee, Michael S. Y. & Fry, Bryan G., 2012, Aipysurus mosaicus, a new species of egg-eating sea snake (Elapidae: Hydrophiinae), with a redescription of Aipysurus eydouxii (Gray, 1849), Zootaxa 3431, pp. 1-18 : 12-13

Aipysurus eydouxii ( Gray, 1849)

Aipysurus eydouxii ( Gray, 1849) ; Boulenger (1896); Flower (1899); Wall (1909); Smith (1926) (part); Smith (1943); Taylor (1965); Lim & Sawai (1975); Lemen & Voris (1981); Kharin (1981); Glodek & Voris (1982); McCarthy & Warrell (1991); Stuebing (1991); Golay et al. (1993) (part); Murphy et al. (1999); David & Ineich (1999) (part); Kharin & Hallermann (2009); Rasmussen et al. (2011)

Tomogaster eydouxii Gray, 1849

Thalassophis anguillaeformis Schmidt, 1852

Thalassophis muraenaeformis Schmidt, 1852

Aipysurus anguillaeformis ( Schmidt, 1852) : Gunther (1864); Krefft (1869)

Aipysurus margaritophorus Bleeker, 1858

Variation in Aipysurus eydouxii . This new characterisation was made following removal of A. mosaicus and is based on 37 specimens (19 adult males, 18 adult females) examined for this study including the type (see Table 2 and Appendix 2).

External morphological characters. One pre- and two postoculars on both sides in 35 specimens, 1-1/2- 2 in two specimens, 1-1/ 1-2 in one specimen, 1-1/ 1-3 in one specimen. Six/six supralabials in 34 specimens, 7/ 6 in two specimens, 7/ 7 in three specimens. First and second supralabials in contact with nasal in 38 specimens, first, second and third in one specimen. Second, third and fourth supralabial in contact with preocular in 22 specimens, second and third in 14 specimens, third and fourth in three specimens. Fourth supralabial in contact with eye in 32 specimens, third and fourth in six specimens, fourth and fifth in one specimen. Two anterior temporals on both sides in 28 specimens, 1/ 1 in two specimens, 1/ 2 in five specimens, 2/ 1 in three specimens and 3/ 3 in one specimen. Six infralabials on both sides in 30 specimens, 7/ 7 in two specimens, 6/ 7 in three specimens, 5/ 6 in one specimen, 7/ 6 in three specimens. Sublinguals well developed and in contact with one another. First, second and third infralabial in contact with anterior pair of sublinguals in 34 specimens, first through fourth in three specimens, first and second in two specimens. Third and fourth infralabials touching posterior pair of sublinguals in 36 specimens, only fourth in one specimen, second and third in two specimens. Scale rows 15–17 on neck in males, 15–17 in females. Scale rows on body 16–17 in males, 17 in females. Fifteen scale rows ten ventrals before vent in males, 13–15 in females. Ventrals 127–143 in males, 136–149 in females, distinct throughout, about three to four times as broad as adjacent scales. Preanals enlarged and split up into two scales. Subcaudals 27–34 in males, 21–27 in females. Snout-vent length in largest male 49 cm, tail length 9.5 cm; largest female 80 cm, tail 11.5 cm.

Internal morphological characters: Tip of heart extending to ventral scale number 47–56 in males, 47–55 in females. %VS-heart 34.5–40% in males, 33.1–39.6% in females. Anterior end of liver situated at ventral scale number 50–58 in males, 49–60 in females. %VS-liver 36.0–42.2% in males, 34.5–41.7% in females. Heart and liver separated by distance between 2–4 ventral scales in males, 1–4 in females. Compared to Aipysurus mosaicus , A. eydouxii has a smaller premaxilla, a larger maxilla, a triangular (rather than crescent-shaped) nasal, a straight (rather than anteriorly concave) frontoparietal suture, and caudal neural spines that lack dorsal expansions ( Fig. 5 ).

Colouration: Head brown or pale brown above, same or paler below. Body usually cream, salmon or yellowish with brown to olive green cross-bands. Bands are broadest dorsally, narrowing on the sides and ventral surface. Scales between bands usually with dark margins. Number of bands on body 30–42 on males, 29–45 in females. Number of bands on tail 7–11 in males, 4–10 in females.

Distribution. Gulf of Thailand, Cambodia, Viet Nam, West Malaysia, Singapore and Java ( Smith, 1926; 1943; David & Ineich, 1999). We also examined two specimens from New Guinea (Port Moresby: BMNH 1954.1.12.95 and “N. Riv. Bvj Bivukeil”: RMNH 5784), but we did not find specimens from the area between the Sunda Shelf and New Guinea in the major museum collections (Berlin, Chicago, Leiden, London and Paris). Boulenger (1896) lists this species as also occurring in the Philippines but to the best of our knowledge no specimens have been collected to confirm this claim ( Taylor, 1922; Herre, 1942; Dunson & Minton, 1978; Alcala, 1986).

Figures

FIGURE 5. Micro-CT images of Aipysurus mosaicus sp. nov. from (A) left lateral and (B) dorsal view of skull, and (C) left lateral view of mid-caudal vertebrae; and Aipysurus eydouxii from (D) left lateral and (E) dorsal view of skull, and (F) left lateral view of mid-caudal vertebrae. Note the differences in the morphology of the premaxilla, maxilla, nasal, frontoparietal suture, and neural spine; see text for fuller discussion. Specimens illustrated are as follows: (A, B) SAMA R 65222 holotype, (C) SAMA R 23493 paratype, (D, E) MZB Ophi 4184, (F) SAMA R 22569.