Gehyra louisiadensis Kraus, 2024, sp. nov.

Gehyra louisiadensis sp. nov. urn:lsid:zoobank.org:act: 8311665D-1E96-4EB8-9133-91D37A8E6B8B Figs. 3E, 4D, 10 Gehyra oceanica Kraus & Shea 2005: 471. Gehyra oceanica Goldberg, Bursey & Kraus 2010: 139 [part]. Holotype.— BPBM 19763 (field tag FK 9893), mature male, F. Kraus, collected at Araeda, Sudest Island, 11.4362° S, 153.4301° E, 1–20 m a.s.l., Milne Bay Province, Papua New Guinea, 28 April 2004. Paratypes (n=14).— Papua New Guinea: Milne Bay Province: Sudest Island: same data as holotype (BPBM 19762), same data as holotype except collected 11 April 2004 (BPBM 19759), ridge N of Camp 1, 11.48° S, 153.41° E, 120–130 m a.s.l., 26 April 2004 (BPBM 19760–61); Rossel Island: Damunu, 11.365° S, 154.001° E, 0–40 m a.s.l., 1 May 2004 (BPBM 19764–67), Cheme, 11.3231° S, 154.2428° E, 5 m a.s.l. 5 May 2004 (BPBM 19768); Misima Island: Liak, 10.6608° S, 152.6854° E, 0–20 m a.s.l., 11–15 January 2003 (BPBM 17218, 17220–22), Bwaga Bwaga Ridge, 10.674° S, 152.683° E, 440–480 m a.s.l., 12 January 2003 (BPBM 17219). Diagnosis.—A medium-sized (SVL of adult males 68.0–83.0 mm, of adult females 53.0–77.0 mm) species of Gehyra having entirely undivided subterminal lamellae on all toes; 11–15 T 4 lamellae; 10–15 T 1 lamellae; moderate amount of webbing between all toes (T 3– T 4webL/ T 4L = 0.17–0.31, T 4– T 5webL/ T 4L = 0.08–0.19); long snout (SN/HL = 0.46–0.51, EN/HL = 0.37–0.42); narrow head (HW /HL = 0.73–0.86); 38–56 enlarged precloacal/femoral scales; 28–55 precloacal/femoral pores in a continuous chevron; a medial row of enlarged subcaudal scales with some smaller scales interspersed; tail depressed, flattened, lacking lateral serrations; skin folds absent on trunk and forearms; popliteal skin fold absent (n = 13) or small (n = 2); elongate postmentals; 1–6 scales in posterior contact with postmentals; three postnasals; all postsupranasal scales small, with none>50% size of supranasal; dorsal color pattern of large, dark-brown, anastomozing maculations on a medium-brown or yellow-brown ground color. Comparisons with other species.—Among Melanesian Gehyra, G. louisiadensis is easily distinguished from G. baliola, G. barea, G. insulensis, G. interstitialis, G. lampei, G. leopoldi, and G. papuana by having undivided (vs. divided) subapical lamellae under the toes. Gehyra louisiadensis differs from G. cf. dubia in having extensive webbing between the digits (vs. absent or only basal in G. cf. dubia); from G. chrysopeleia, G. georgpotthasti, G. marginata, G. membranacruralis, and G. rohan by its much smaller size (up to 83 mm SVL in G. louisiadensis vs.> 100 mm in those other species), lack of popliteal and antecubital skin folds (vs. prominent skin folds in those other species), and fewer T 4 lamellae (11–15 vs. 16–27 in those other species); and from G. serraticauda in its smaller size (up to 83 mm SVL vs. 90 mm SVL in G. serraticauda), absence of lateral serrations on the tail (vs. present in G. serraticauda), and dorsum boldly maculated with dark brown (vs. dorsum gray with or without red markings in G. serraticauda). Gehyra louisiadensis is most similar to G. oceanica and G. maculicincta. It differs from G. oceanica in its generally smaller size (up to 83 mm SVL vs. up to 102 mm in G. oceanica), fewer T 4 lamellae (11–15, mean 13.8 vs. 13–19, mean 15.7 in 157 Polynesian G. oceanica, 15–20, mean 17.7 in 80 Micronesian G. oceanica); medial row of enlarged subcaudal scales (vs. subcaudals small and subequal in G. oceanica); and color pattern of large dark-brown maculations on a lighter-brown ground (vs. dorsum uniform gray, brown, or with small scattered spots but not boldly maculated in G. oceanica). These meristic differences are most clear in a bivariate plot of numbers of precloacal/femoral pores vs. numbers of T 4 lamellae (Fig. 8). Gehyra louisiadensis differs from G. maculicincta in its larger size (up to 83 mm SVL vs. up to 69.5 mm in G. maculicincta), greater number of T4 lamellae (11–15, mean 13.8 vs. 11–13, mean 12.4 in G. maculicincta), greater number of T1 lamellae (10–15, mean 11.8 vs. 8–11, mean 9.8 in G. maculicincta), medial row of enlarged subcaudal scales (vs. subcaudals small and subequal in G. maculicincta), relatively narrower head (HW/HL = 0.73–0.86, mean 0.80 vs. 0.80–0.94, mean 0.89 in G. maculicincta), and dorsum with large dark-brown maculations on a medium-brown or yellow-brown ground color (vs. dorsum with alternating bands of bold dark-brown and pale yellow-tan spots in G. maculicincta). Description of holotype.—A mature male of medium size (SVL = 72.5 mm) with a right-lateral incision behind the pectoral region; liver removed for molecular studies and most viscera removed for prior parasite studies. Head relatively long (HL/SVL = 0.23) and narrow (HW/HL = 0.83), distinct from neck (Fig. 10A). Loreal region slightly inflated; no distinct canthus rostralis. Top of snout concave, area behind nares shallowly concave. Snout tapered and rounded at tip, relatively long (SN/HL = 0.48), almost twice eye diameter (SN/EY = 1.9). Eye of modest size (EY/HL = 0.26, EY/EN = 0.65); pupil vertical, constricted into four lobes; anterior supraciliaries slightly larger than adjacent granules and posterior supraciliaries, remainder subequal to adjacent granules. Ear opening of moderate size (Ear/HL = 0.095), squarish; distance between ear and eye one-third again as large as eye diameter (EE/EY = 1.3). Rostral approximately half again as wide (3.0 mm) as high (1.9 mm), highest medial to supranasals, lower medially, with medial suture on dorsal quarter; length 1.0 mm. Single large internasal separates supranasals, with smaller internasal between this and rostral. Rostral in contact with first supralabials, two supranasals, and two internasals (narrow contact only with larger, posterior internasal). External nares circular; each bordered by rostral, single supranasal, first supralabial, and three postnasals. Each supranasal bordered posteriorly by three (R) or four (L) small postsupranasals, all <<50% size of supranasal. Mental triangular, 2.8 mm wide, rear margin slightly scalloped. Mental bordered posteriorly by two elongate postmentals that are longer than mental (Fig. 10B), these each bordered posteriorly by two round scales slightly larger than chin granules. Two shorter subinfralabials lie sequentially lateral to each postmental, decreasing in size posteriorly. First infralabial bordered below by postmental and first subinfralabial, second by both subinfralabials and a smaller round scale, and third by four small scales; subinfralabials behind this increasingly smaller, becoming granular posteriorly. Supralabials to mid-orbital position nine on each side; four tiny supralabials posterior to this; angle of jaw bordered with granular scales. Infralabials ten on each side. Body of fairly robust habitus (TrL/SVL = 0.43), slightly depressed. Dorsal scales on head, body, limbs, throat, and tail small juxtaposed granules; tubercles absent. Ventral scales larger, flat, smooth, subimbricate, larger midventrally, gradually decreasing in size laterally to become granular. Skin folds absent on body and limbs. Enlarged precloacal/femoral scales in series of 26 scales on right side (absent from left), containing 24 pores extending in a curve from center of precloacal region to center of thigh (Fig. 10D), pores larger medially, smaller laterally; thigh scales anterior to this row flat, subimbricate, larger than those immediately posterior to row; enlarged scales anterior to pore-bearing series extending laterally along most of length of pore series but decreasing in size near lateral end of pore series. Enlarged, imbricate scales form a pubic patch between precloacal series and vent, smaller anteriorly, larger posterior to that, then decreasing slightly in size posteriorly to vent; 12–13 scales in a row between apex of enlarged precloacal series and vent. Scales under arms flat, small, subimbricate; those under hindlimbs larger, flat, imbricate; scales on palms and soles granular to subimbricate. Fore- and hindlimbs well-developed (FA/SVL = 0.11, CS/SVL = 0.13). Digits well-developed, with broad pads on toes (T4W/T4L = 0.46), all but first fingers with well-developed recurved claws; clawed terminal phalanges on all digits except T1 laterally compressed, free above, arising from toe pad, inset from its margin, extending slightly beyond it; claw on T1 small, terminal, extending slightly beyond toe-pad margin. Subdigital lamellae narrow and smooth, all undivided, most forming a shallowly curved chevron medially (Fig. 10C); lamellae extend for two-thirds length of each toe (T4lamellaeL/T4L = 0.65). Lamellae of manus 12-13-14-13-13 on right, 12-13-14-14-13 on left; of pes 13-14-14-15-15 on right, 13-13-15-15-15 on left. Relative lengths of digits on manus and pes I <II <III <V <IV. Webbing present between all digits, reduced on hands, most extensive between T3 and T4 (T3T4webL/T4L = 0.22, T4T5webL/T4L = 0.19). Tail relatively long (TL/SVL = 0.68), wide (TW/SVL = 0.11) and flattened, no lateral serrations; approximately 4–6 mm of tip missing. Tail constricted slightly just behind cloacal sacs, denoting fracture plane, but scale size and arrangement and coloration continuous on either side of this constriction, suggesting tail is original. Dorsally, tail with granules anteriorly, becoming slightly larger and subimbricate posteriorly; under tail with midventral row of enlarged hexagonal scales and smaller scales laterally (Fig. 3E); lateral scales decreasing in size laterally and posteriorly. Cloacal sacs swollen, with single oblong external orifice situated near each lateral margin of vent; four slightly enlarged, blunt postcloacal spurs on each side of tailbase; midventral scales of sac flat, subimbricate, larger posteriorly, slightly larger than those ventrolaterally. Color in preservative: Dorsal ground color on body, head, limbs, and tail medium brown, with small, slightly darker-brown scattered flecks. Supralabials medium bro