Brachyorrhos albus ( Linnaeus, 1758 )

Murphy, John C., Mumpuni, Lang, Ruud de, Gower, David J. & Sanders, Kate L., 2012, The Moluccan Short-Tailed Snakes Of The Genus Brachyorrhos Kuhl (Squamata: Serpentes: Homalopsidae), And The Status Of Calamophis Meyer, Raffles Bulletin of Zoology 60 (2), pp. 501-514 : 507-508

Brachyorrhos albus ( Linnaeus, 1758)

( Fig. 4a )

Coluber albus Linnaeus, 1758: 128

Holotype. — NRM19 ( Sweden) not described here

Type Locality. — “Indiis” ( Ambon, Indonesia)

Brachyorrhos albus Kuhl in Schlegel, 1826: 236

Calamaria brachyorrhos Müller, 1857: 39

Material Examined. — Ambon: Waai – FMNH 134322–24, 142332, 142145–46; MZB 1524A–B. No specific locality – MSNG 30192a;

Seram: Honititoe – FMNH 109949, 119654; BMNH 442222, 6312425; Saunulu – MZB 2364; RMNH 576; ZMA 10494(2); ZMA 10104(2). Pulau Bisa – MZB 2609.

Diagnosis. — A distinct preocular scale present; seven upper labials, fourth (rarely 3+4) in the orbit, sixth is the tallest; dorsal scales more lanceolate (elongated and taper posteriorly) than congeners; usually a single temporal scale contacting the postoculars in the Ambon population; two primary temporals in some Seram individuals. The preocular scale will readily distinguish this species from most other members of the genus. About 35% of B. raffrayi have preoculars, but they have the third (rarely 3+4) upper labial in the orbit and the third is the tallest. Some B. wallacei also have a preocular, but they have higher ventral (more than 168) and subcaudal counts in both sexes, and a venter that has diffuse dark pigment.

Description. — Rostral visible from above and separates the nasals; nasals are divided or semi-divided with the nostril in the anterior portion of the scale; prefrontal and loreal fused into a large shield; preocular scale single, in 3/26 sides the preocular is fused with loreal-prefrontal forming a large shield that makes contact with the upper labials and the orbit. Large occipital scales make contact with the temporal scale(s). Seven upper labials, 2–3 or 2–4 make contact with the fused loreal-prefrontal shield; the fourth upper labial enters the orbit with the third sometimes making very narrow contact; the sixth upper labial is the tallest. Lower labials seven, rarely eight, the first pair makes contact on the midline of the chin posterior to the mental, first four contact the chin shields. Ambon specimens have a single primary temporal scale; Seram specimens have one or two primary temporals. Table 3 compares the island populations for meristic traits. Dorsal scales smooth, in 19 rows, the number of rows on the neck may be 20 by exception, and there is no posterior reduction in scale row numbers. Ventrals 159–173 in males, 171–178 in females. Subcaudal scales are 23–36, with male specimens having more subcaudal scales, and longer tails than females (N = 5, = 24.6, SD =1.52) specimens. Two sample t-tests found the ventrals (p = 0.01) and subcaudals (p <0.01) sexually dimorphic in this species.

Size. — Brachyorrhos albus males have SVLs that ranged from 337–472 mm (N = 12, = 393.09, SD = 39.24); tails were 32–61 mm (N = 10, = 55.75, SD =4.55); females had SVLs of 343–443mm (N = 5, = 373.6, SD = 36.52); tails were 33–41 mm (N = 5, = 36.00, SD = 3.1).

Biology. — Almost everything known about the biology of species in the genus comes from Brachyorrhos albus . B. albus hides by day beneath stones and logs and becomes active at dusk, in search of prey ( Kopstein, 1926). On Seram it was found in lowland secondary forest, plantations and gardens, but also in human habitations at all altitudes. It is nocturnal, terrestrial and occasionally arboreal (Edgar & Lilley, 1993). One Seram specimen was found behind a village shed (De Lang &Verhaart, 2009). Brachyorrhos albus is viviparous, one female (SVL 350 mm) from Seram (FMNH 109949) contained four near term embryos (136–147 mm in total length). The remains of annelid worms (including setae) were recovered from the digestive systems of several specimens, including FMNH142324 from Ambon (Murphy unpublished; Sanders unpublished).

Distribution. — Ambon and Seram. B. albus has been reported from Haruku, Nusa Laut, and Saparua ( Kopstein, 1926), all satellites of Seram. We have not seen snakes from these populations but Kopstein’s (1926) scale counts fit within our data. B. albus has also been reported from the Banda Islands ( Boettger, 1892), without reporting scale counts; this locality needs verification. In addition, one specimen from Pulau Bisa (MZB 2609) is very similar to this species.

Figures

Fig. 4. A comparison of the labial architecture for four species of Brachyorrhos: (A) B. albus (FMNH 134323) Ambon; (B) B. gastrotaenius (BMNH 6312425) Buru holotype; (C) B. raffrayi (MNHN 5174) Ternate, holotype; (D) B. wallacei (MZB 3463) Halmahera holotype. Labials are numbered, T denotes tallest labial; P = preocular; PFL = prefrontal-loreal shield; PLP = preocular-loreal-prefrontal shield.