Laticauda saintgironsi n.sp.

Laticauda saintgironsi n.sp. View in CoL

Holotype. Australian Museum, Sydney ( AMS) R162999 (AMS field no. 34602), an adult male from Porc-épic Island , Le Lagon, near Noumea , New Caledonia collected by the authors on 14 September 1993, 22°19'45.6"S 166°34'08.5"E. GoogleMaps

Paratypes. All paratypes are from localities within New Caledonia and are lodged in the Australian Museum, Sydney ( AMS): R78031 ♂, R78032 ♀, R78035 – 38 ♀♀, R78042 ♀, R78043 ♂, R78046 ♀ from Île Mouac; R109668 ♂, R109669 – 70 ♀♀, R109671 – 73 ♂♂, R109674 ♀, R109690 ♂, R109691 ♀, R109692 ♂, R109693 ♀, R109694 – 98 ♂♂, R109699 ♀ from Île Redika; R109681 ♀, R109682 – 83 ♂♂, R109684 ♀, R109685 ♂, R109686 ♀, R109687 ♂, R 109688 i, R109689 ♀ from Île Grand Mato; R109623 – 24 ♀♀, R109625 ♂, R109659 ♂, R109660 – 62 ♀♀, R109663 ♂, R109664 ♀, R109665 ♂, R109666 ♀; R164882 – 83 ♂♂, R164884 ♀, R164885 – 86 ♂♂, R164887 ♀, R164888 i, R164889 – 93 ♂♂, R164894 ♀, from Île Porc épic, near Noumea ; R78086 ♂ from Île Noue; R144070 – 71 ♀♀, R144072 – 73 ♂♂ from near Ouenguie Village , c. 20 km north of Hienghene; R144065 ♂ from south of Mou , east coast ; R144069 ♂ from c. 5 km SE of Koulnoue Village, near Hienghene ; R144094 – 96 ♂♂ from near Malabou Beach Hotel , Baie de la Nehoue , c. 5 km S of Poum. The letter i refers to immature/indeterminate specimens.

Other specimens examined included living individuals that were weighed, measured and scalation examined before being released back into the wild; other specimens examined by one of the authors (HFH) are listed and discussed in Heatwole et al. (2005).

Diagnosis. A banded sea krait of the genus Laticauda characterized by the possession of a yellow or cream upper lip, an undivided rostral scale, usually 21 mid-body scale rows in both sexes (but occasionally 23 or rarely 25 rows, mode 21 in both sexes), ventral scales from 211 to 224 in males and from 215 to 230 in females, and a maximum snoutvent length (SVL) of 817 mm (males) and 1090 mm (females). It can be distinguished from L. laticaudata and L. crockeri by its yellow upper lip (black or dark brown in laticaudata and crockeri) and from L. semifasciata and L. schistorhyncha by its pale upper lip and undivided rostral (upper lip brown and rostral divided in semifasciata and schistorhyncha).

From the nearest populations (Fiji and Vanuatu) of its allopatric congener L. colubrina it may be distinguished by a lower modal mid-body scale row count of 21, its lower ventral scale counts (Table 1, Fig. 8 View Fig ); smaller size (Table 1); dark body bands either not meeting ventrally or narrowing ventrally, often with a pale mid-ventral blotch; and its distinctive body colour in which the paler bands are predominently brown (fawn to rich russet vs steely grey or blue in L. colubrina).

From L. frontalis is may be distinguished by its larger size and higher ventral and subcaudal counts (Table 1) and the distinctive brown dorsal colour (grey or blue-grey in frontalis).

Description of the holotype. A typical member of the Laticauda colubrina complex in shape, with a relatively slender body in which the mid-body diameter is contained 33.3 times in its snout-vent length and the head is scarcely wider than the neck. Head width (widest point) 16.2 mm, head length (snout tip to rear edge of quadrate) 21.8 mm, the latter representing 3.0% of snout-vent length. The rostral is undivided, about as broad as deep, and separates the nasals, each of which contacts the single preocular scale on each side. The internasals are about as large as the prefrontals, meeting broadly in the middle. The prefrontals are separated posteriorly by a large azygous scale, about equal in size to one of the internasals. A single, large supraocular scale on either side of the frontal. The latter is only slightly longer than broad.Six supralabials on each side, the third and fourth entering the eye. One anterior temporal scale on each side, and two posterior temporals. Six or seven infralabials, though the counts are uncertain because all but the first three infralabials are excluded from the lip by an irregular series of splint-like marginal scales.

There are 21 mid-body scale rows. Body scale row numbers are reduced only posteriorly, with 21 rows at the 20th, 50th, 100th and 150th ventrals and 19 rows at the 200th ventral. There are 218 ventral scales and 38 pairs of subcaudal scales. The snout-vent length (SVL) in life was 727 mm, while the tail length was 88 mm. The live weight was 185 g.

The colour pattern (Figs. 2 and 3) consists of a broad black band across the back of the head, extending forward to about the middle of the frontal scale; this band is joined laterally on each side by a broad dark stripe from behind the eye and another continuous black stripe below each lower jaw. At the point where these all meet there is a broad lateral black bar linking the dark head band to the first neck band. There are 28 black bands on the trunk and four on the tail. All of these black bands extend right around the body, but most trunk bands also have a pale, mid-ventral blotch. Along the vertebral line the pale bands between the black bands are 60–66% as wide as the black bands.

In life, the colour of the holotype from above was bright russet-orange, fading gradually on the flanks to a pale cream or white, but with many of the individual scales tipped or edged with black or dark blue-grey, giving the pale bands a reticulated appearance; the dark bands were glossy black. Ventrally the colour was creamy-white, with the margins of the ventral scales slightly darker-edged with pale brown. Most of the scales on the head and lips are finely margined with black, emphasizing the sutures.

Variation. The general appearance and non-diagnostic scalation varies little from that described for the holotype above. As in all Laticauda there is marked sexual dimorphism in body mass and relative tail length, sometimes exaggerated in older (larger) individuals Variation in those principal morphological characters used in diagnosing the species are given in Table 1 and Figs. 4–7 View Fig View Fig View Fig View Fig . In both cases the variables for Laticauda saintgironsi are compared with those in adjacent regional populations of both Laticauda colubrina and Laticauda frontalis.

The number of scale rows around the body (excluding the ventrals) varies along the length of the body, as shown in Table 1 for (usually) five points along the body—at the 20th, 50th, 100th, 150th and either the last or 200th ventral (whichever came first), but the mid-body count is mostly 21 in males and females ( Fig. 9 View Fig ) and only occasionally 23 or 25. The ventral scales range from 211–230 (Table 1, Fig. 8 View Fig ) and the paired subcaudal scales range from 25–42 (37–

L. saintgironsi vs. L. frontalis F 1–112 = 3.704 p = 0.057

L. saintgironsi vs. L. colubrina (Fiji) F 1–111 = 19.932 p <0.001

L. saintgironsi vs. L. colubrina (Vanuatu) F 1–109 = 2.128 p = 0.147

L. colubrina (Fiji) vs. L. frontalis F 1–85 = 4 p <0.001

L. frontalis vs. L. colubrina (Vanuatu) F 1–83 = 5.561 p = 0.021

L. colubrina (Fiji) vs. L. colubrina (Vanuatu) F 1–82 = 2.727 p = 0.103

L. frontalis vs. L. saintgironsi F 1–40 = 13.783 p = 0.001

L. saintgironsi vs. L. colubrina (Fiji) F 1–55 = 3.582 p = 0.064

L. saintgironsi vs. L. colubrina (Vanuatu) F 1–78 = 1.791 p = 0.185

L. frontalis vs. L. colubrina (Fiji) F 1–49 = 9.129 p = 0.004

L. frontalis vs. L. colubrina (Vanuatu) F 1–72 = 7.102 p = 0.009

L. colubrina (Fiji) vs. L. colubrina (Vanuatu) F 1–87 = 0.767 p = 0.384

L. saintgironsi vs. L. frontalis F 1–52 = 0.213 p = 0.647

L. colubrina (Fiji) vs. L. colubrina (Vanuatu) F 1–85 = 133.073 p <0.001

L. saintgironsi vs. L. colubrina (Vanuatu) F 1–92 = 2.578 p = 0.112

L. colubrina (Fiji) vs. L. frontalis F 1–69 = 49.749 p <0.001

L. frontalis vs. L. colubrina (Vanuatu) F 1–76 = 0.336 p = 0.564

L. colubrina (Fiji) vs. L. colubrina (Vanuatu) F 1–109 = 56.594 p <0.001

L. saintgironsi vs. L. frontalis F 1–52 = 0.213 p = 0.647

L. colubrina (Fiji) vs. L. colubrina (Vanuatu) F 1–85 = 133.073 p <0.001

L. saintgironsi vs. L. colubrina (Vanuatu) F 1–92 = 2.578 p = 0.112

L. colubrina (Fiji) vs. L. frontalis F 1–69 = 49.749 p <0.001

L. frontalis vs. L. colubrina (Vanuatu) F 1–76 = 0.336 p = 0.564

L. colubrina (Fiji) vs. L. colubrina (Vanuatu) F 1–109 = 56.594 p <0.001

42 in males, 25–34 in females, Table 1). The total number of dark body bands ranges from 23–29 (males) and 21–30 (females), while the number of dark tail bands ranges from 3–4 (males) and 2–3 (females).

Distribution. Known only from the French Territory of New Caledonia, where it occurs around the entire coast of the main island (Grande Terre) and its many offshore islands, often in very large numbers locally. It is recorded from the Loyalty Islands, but there are no current records there of syntopy with its closest congener, Laticauda frontalis.

Ecology. This is a typical member of the Laticauda colubrina complex, spending much of its time in coastal waters feeding on a variety of eels in shallow reef waters, alternating with periods spent ashore sheltering in shoreline vegetation, piles of dense litter, or, on rocky shorelines, in crevices and caves, or under boulders. They may travel some hundreds of metres inland, and climb to the tops of rocky hills and islands that may be 100 m or more in elevation. Aggregations of 30 or more individuals are often encountered in single refuges, while some hundreds of individuals may be found on individual small islands within the lagoons of large reef systems.

An extensive summary of the distribution and ecology of this species, under the name Laticauda colubrina, has recently been provided by Ineich & LaBoute (2002). Other studies, also as L. colubrina, include St Girons (1964), McCarthy (1986) and Shine et al. (2003). The species is abundant and wide-ranging around the coast of New Caledonia and its numerous off-shore islands.

Etymology. This species in named for the late Dr Hubert Saint Girons, whose many outstanding contributions to international herpetology ranged across disciplines and continents. In order for future workers to clearly identify the patronym, the name saintgironsi is formed directly from the modern personal name as a noun in the genitive case.