Celatiscincus similis, Sadlier & Smith & Bauer, 2006

Sadlier, Ross A., Smith, Sarah A. & Bauer, Aaron M., 2006, A New Genus for the New Caledonian Scincid Lizard Lygosoma euryotis Werner, 1909, and the Description of a New Species, Records of the Australian Museum 58 (1), pp. 19-28 : 22-23

Celatiscincus euryotis Werner, 1909

Figs. 1 , 2

Material examined. AMS R138528–46, R138569–70, R138572–77, R138620, CAS 182089–108, 182118–27, 182140–45, 182181, 182186– 88, 182199 New Caledonia, Province Sud, Isle of Pines, Gite Kodjeue on Waa Mé Bay, 22°34'S 167°25'E; AMNH 81783 New Caledonia, Province Sud, Isle of Pines, Vao; and CAS 80889 and IRSNB 2.025 Isle of Pines—no specific locality.

Diagnosis. Celatiscincus euryotis is distinguished in morphology from Celatiscincus similis n.sp. (the only other species in the genus) by differences in adult colouration and osteology. Adult male Celatiscincus similis n.sp. have a bright russet flush to the body around the area of the hindlimbs, and adult females a bright russet flush to the whole of the tail, whereas these colours are muted in Celatiscincus euryotis (see also Bauer & Sadlier [1994] for a discussion of colour in C. euryotis). Celatiscincus euryotis has fewer presacral vertebrae (mode 28) than Celatiscincus similis n.sp. (mode 29). These differences in colouration and osteology are supported by DNA sequence data (see section on relationships below).

Description. Based on 28 specimens (33.0–42.0 mm SVL) in the AMS collection, comprising 12 adult males, 14 adult females, and 2 subadults.

Measurements: maximum SVL of males 42.0 mm, females 40.0 mm; distance from axilla to groin 48.5–56.4% of SVL (¯x = 52.0%, n = 28); distance from forelimb to snout 37.5–45.5% of SVL (¯x = 41.2%, n = 28); hindlimb length 38.1–44.3% of SVL (¯x = 41.1%, n = 27); tail length 151.4% of SVL for adult individual with most complete tail.

Scalation: Midbody scale rows 30–36 (¯x = 33.1±1.26, n = 28); paravertebral scales 49–57 (¯x = 52.4±2.20, n = 28)— no sexual dimorphism between 12 males and 14 females (¯x 52.33 vs 52.57, t 24 = -0.27, P<0.792); scales on top of fourth finger 8–10 (¯x = 8.9±0.38, n = 27); lamellae beneath fourth finger 15–18 (¯x = 16.2±0.68, n = 26); scales on top of fourth toe 11–13.5 (¯x = 12.75±0.57, n = 36); lamellae beneath fourth toe 30–40 (¯x = 35.3±1.87, n = 33).

Osteology: presacral vertebrae 28 (n = 14)–29 (n = 3); postsacral vertebrae 41 (specimen with most complete tail showing no evidence of regeneration); phalangeal formula for manus and pes 2.3.4.5.3 and 2.3.4.5.4 respectively.

Colouration: There is marked sexual dimorphism between adult males and females, with subadults and juveniles similar in colouration to adult

females.

Adult males (Fig. 1): dorsal and lateral surface tan-light scattered dark surface, and a snout in some flush to the basal moderate yellow underside of hindlimbs and tail. Throat with an obvious pattern of dark transverse markings on the outer chinshields and throat scales, and a variably defined, narrow, dark, longitudinal streak on the throat and chest.

brown or mid brown, with a few flecks on the anterior and upper lateral continuous, narrow, dark stripe across the specimens. In life with an orange to russet portion of the tail and hindlimbs, and a flush to the posterior half of the abdomen,

Adult females ( Fig. 1 ): body usually two-toned, but the degree of differentiation between the dorsal and lateral surfaces varies. Dorsal surface of the body dull light-brown or mid-brown. Lateral surface light-mid grey with scattered dark flecking overall, boldly marked individuals with these darker markings covering most of the lateral surface and contrasting markedly with the paler dorsal colour. Dark markings on dorsal surface aligned as a concentration of longitudinal flecks along dorsolateral margin, tending to form a continuous, narrow, dark stripe along the temporal margin, and across the snout in some specimens. A narrow, white, hip stripe (dark-edged above) extends along basal portion of tail and over the hindlimbs, continuing as a pale, narrow upper edge (paler than hip stripe) to the dark dorsolateral markings, extending to near the temporal region in some specimens. In life with a dull orange flush to the lateral, dorsal, and ventral areas of the entire tail, remainder of underside of body and hindlimbs white.

Subadults—overall body colouration usually darker with dark lateral flecking extending over most of the lateral surface, otherwise subadult males have a colour pattern typical of adult females and juveniles including a weak to obvious pale hip stripe and a continuous concentration of dark flecks along the dorsolateral margin in the shoulder region—ventral colouration of pale.

Reproduction: The series collected during the wet season in early March 1992 contained a high proportion of gravid females which consistently showed an egg laying mode of reproduction with a clutch size of 2–3 shelled oviducal eggs.

Distribution and habitat. The species is known only from the Ile of Pines, approximately 50 km southeast of the southern coast of the Grande Terre ( Fig. 2 ). Its distribution on the island and surrounding islets may be very localised. A recent survey of islets off the Ile of Pines did not reveal the presence of the species at any of those examined.

Figures

Fig. 1. Celatiscincus euryotis, an adult male (above) and adult female (below) from Waa Mé Bay, Isle of Pines, New Caledonia.

Fig. 2. Distribution of Celatiscincus euryotis and Celatiscincus similis n.sp. in New Caledonia.