Lobulia huonensis, Slavenko & Tamar & Tallowin & Kraus & Allison & Carranza & Meiri, 2022

Slavenko, Alex, Tamar, Karin, Tallowin, Oliver J S, Kraus, Fred, Allison, Allen, Carranza, Salvador & Meiri, Shai, 2022, Revision of the montane New Guinean skink genus Lobulia (Squamata: Scincidae), with the description of four new genera and nine new species, Zoological Journal of the Linnean Society 195 (1), pp. 220-278 : 254-256

LOBULIA HUONENSIS SP. NOV.

HUON MOSS SKINK

( FIGS 6 , 11–12 ; TABLE 1 )

Z o o b a n k r e g i s t r a t i o n: u r n:l s i d: z o o b a n k. org:act: 692113B4-B03F-4D41-8620-7DE7852BDA1B

Holotype: BPBM 40322 (field tag AA 20573), adult male, collected by A. Allison at Dopeke, 5.9538°S, 146.5573°E (WGS 84), 2646 m a.s.l., Finisterre Range , Madang Province, Papua New Guinea, 3 October 2010.

Paratypes (N = 18): Papua New Guinea: Morobe Province: Saruwaged Range: Tobo , 6.367°S, 147.37°E (WGS 84), 1600 m a.s.l. (BPBM 2893; male) ; Madang Province: Finisterre Range: same locality as holotype (BPBM 40320, 40323; one male, one female) ; Wil, near Teptep , 5.9438°S, 146.5549°E (WGS 84), 2359 m a.s.l. (BPBM 40321, 40330–31; two males, one female) ; ridge N of Teptep, 5.9369°S, 146.5499°E (WGS 84), 2662 m a.s.l. (BPBM 40324, 40327, 40332; one male, one female, one juvenile) ; c. 1.6 km NW of Teptep, 5.9392°S, 146.5523°E (WGS 84), 2556 m a.s.l. (BPBM 40325; male) ; c. 11 km WNW of Teptep, 5.9365°S, 146.5487°E (WGS 84), 2686 m a.s.l. (BPBM 40326; male) ; c. 2 km NNW of Teptep, 5.9339°S, 146.5567°E (WGS 84), 2564 m a.s.l. (BPBM 40328–29; one male, one female) ; Siwasiwa, 5.9377°S, 146.5592°E (WGS 84), 2440 m a.s.l. (BPBM 40333; juvenile) ; Siwasiwa Camp, near Teptep , 5.9464°S, 146.5601°E (WGS 84), 2478 m a.s.l. (BPBM 40334, 40337; two males) ; vicinity of Teptep Station , 5.9552°S, 146.5595°E (WGS 84), 2173 m a.s.l. (BPBM 40335; female) ; “ca. 2 km NW of Teptep ”, 5.9334°S, 146.5336°E (WGS 84), 2687 m a.s.l. (BPBM 40336; male) .

Diagnosis: A medium-sized species of Lobulia (adult SVL 45.2–63.9 mm), characterized by the unique combination of frontoparietals unfused; supraorbital ridges not pronounced; nuchals 1–3 pairs; paravertebral scales 59–68; mid-body scale rows 33–38; 4 th digit on front foot longer than 3 rd; subdigital lamellae 19–25 under 4 th toe; single supradigital scales 3–4 on 4 th toe; mid-dorsum with two rows of large dark brown spots on an olive green background; top of tail base with two rows of large dark brown spots; fragmented white dorsolateral stripes present, extending from parietals to base of tail; flanks dark brown with light spots; unbroken white lateral stripes present, extending from occiput to hindlimbs; ventral coloration light blue on chin, light blue to lemon yellow on abdomen and base of tail in life, uniform light blue in preservative; thighs and precloacal region lack brown spotting; ventral surfaces of tail speckled with light brown spots forming fragmented parallel longitudinal lines; palmar and plantar surfaces pale to lemon yellow in life, light brown in preservative.

Comparisons: Lobulia huonensis differs from Lo. brongersmai in having unfused (vs. fused) frontoparietals. It differs from Lo. elegans and Lo. fortis in having white dorsolateral stripes and lateral stripes (vs. absent). Lobulia huonensis is most similar in scalation and general habitus to Lo. lobulus . It differs from it in dorsal coloration—whereas Lo. lobulus has dorsal rows of dark brown spots joined to form two mid-dorsal stripes, Lo. huonensis has large mid-dorsal dark brown spots arrayed in parallel longitudinal rows (not creating stripes), giving it an overall “lighter” appearance—and in having a higher average count of paravertebral scales [62.7 (59–68) vs. 57.7 (54–61)].

Description of the holotype: Rostral broad and shallow, wider than deep, projecting slightly onto top of snout; nasals more or less rectangular, separated by rostral and frontonasal contact, projecting anterodorsally onto dorsum of snout; nostril circular, centred within nasal; frontonasal large, with eight sides, extending laterally to slightly above the level of nares, in broad contact with frontal; prefrontals large, separated by frontonasal and frontal contact, bordered lateroventrally by two loreals; supraoculars four, anterior two in contact with frontal, posterior three in contact with frontoparietals; frontal roughly kite shaped, widest anteriorly; frontoparietals single pair in medial contact, in narrow contact with frontal; interparietal of roughly similar area to single frontoparietal, kite shaped, widest anteriorly; parietal eye spot absent; parietals in contact behind interparietal, in contact anteriorly with frontoparietals, posteriormost supraocular and two pretemporals; nuchals single pair, transversely enlarged, wider than long, separated from secondary temporal by a single intercalated scale. Anterior loreal smaller than posterior loreal, higher than long; posterior loreal longer than high; lower preocular roughly square in shape; upper preocular much smaller, longer than high; presubocular single; postsuboculars four, lowest interdigitated between subocular supralabial and penultimate supralabial; lower eyelid scaly, moveable, with a clear palpebral disc smaller than size of ear opening; supraciliaries eight, anteriormost not in contact with frontal, posteriormost projecting medially and interdigitated between posteriormost supraocular and upper pretemporal; primary temporals two, lower interdigitated between posterior two supralabials; secondary temporals two, upper larger and overlapping lower; supralabials seven, fifth in contact with small scales of lower eyelid; postsupralabials two; ear opening moderately large, with lobules along anterior margin. Mental single; postmental single, contacting two anteriormost infralabials; infralabials eight; enlarged chin shields four pairs, the first two pairs in medial contact, third pair narrowly separated by single medial scale, fourth pair separated by three medial scales; posteriormost chin shield in contact with penultimate infralabial. Body scales smooth, in 36 rows at midbody; paravertebral scales 67; medial precloacal scales enlarged, overlapping lateral precloacals. Scales on dorsal surface of 4th toe in two rows proximally, single row distally beginning at third interphalangeal joint, three single scales; subdigital lamellae under 4th toe 23, smooth. In preservative ( Fig. 11 ), base dorsal coloration coppery brown, with two mid-dorsal parallel rows of large dark brown spots two to four scales long, extending to base of tail; spots become smaller posteriorly on tail; dorsolateral stripes present as light blue fragmented stripes extending from occiput to base of tail; lateral field dark brown, speckled with light blue spots one to two single scales wide; unfragmented light blue lateral stripe present, extending from postsupralabials, across ear opening, to hind limbs; head similar in coloration to dorsum, with dark brown spotting, mostly in centre of scales and along scale margins; ventral surfaces uniform light blue; light brown dusting present on ventral surface of tail, roughly forming parallel longitudinal rows along tail margins; scales on palmar and plantar surfaces light brown, contrasting with dark brown digits. In life ( Figs 6 , 12 ), dorsal colour coppery brown with black mid-dorsal spots; fragmented dorsolateral stripes, uniform lateral stripes and spots on lateral field white; chin light blue; ventral surfaces of chest, abdomen, thighs, precloacal region and tail lemon yellow, with tail becoming light blue posteriorly; scales on palmar and plantar surfaces lemon yellow.

Variation: Adult body size 45.2–63.9 mm SVL (mean = 54.0, SD = 4.7, N = 17). Females (mean = 51.8, range: 45.2–63.9, SD = 7.2, N = 5) have larger maximal size than males (mean = 56.5, range: 51.5– 60.2, SD = 3.2, N = 12). Forelimbs 37.7–43.6% of SVL (mean = 42.1%, SD = 1.7, N = 17). Hindlimbs 46.1– 51.9% of SVL (mean = 49.8%, SD = 1.6, N = 17). Scale rows at midbody 33–38 (mean = 36.2, SD = 1.3, N = 19); paravertebral scales 59–68 (mean = 62.7, SD = 2.6, N = 18). Lamellae under 4th toe 19–25 (mean = 21.3, SD = 1.3, N = 19); single supradigital scales on 4th toe 3–4 (mean = 3.1, SD = 0.3, N = 19). Mostly 1–3 pairs of nuchals, but BPBM 40323, 40325, 4027, 40328, 40333 and 40325 have an asymmetrical number of nuchals, with either one more nuchal on right side (BPBM 40327) or on left side (all others). Primary nuchals usually separated from secondary temporals by a single smaller intercalated scale (N = 16), rarely by two on left side and one on right (N = 2) or none on left side and one on right (N = 1). Prefrontals usually separated by frontonasal and frontal contact (N = 16), rarely by a single azygous scale (N = 3). Supraciliaries rarely seven (N = 1), typically eight (N = 9), occasionally nine (N = 7) or ten (N = 2). Anteriormost supraciliary usually not in contact with frontal (N = 14), sometimes in narrow contact (N = 5). Postsuboculars usually three (N = 16), rarely four (N = 2) or two (N = 1). Supralabials almost always seven (N = 18), rarely nine (N = 1). Primary temporals either single (N = 13) or two (N = 6). Infralabials rarely six (N = 1), typically seven (N = 13), occasionally eight (N = 3) and rarely nine (N = 1). Infralabials posterior to contact with chin shields usually one (N = 18), rarely two (N = 1).

Colour pattern of all examined specimens generally similar to holotype, with few exceptions. Size of middorsal dark brown spots varies between individuals. BPBM 40320, 40326 and 40328 have unfragmented, as opposed to fragmented, dorsolateral stripes. BPBM 2893, 40325 and 40331 have fragmented, as opposed to unfragmented, lateral stripes. BPBM 40334 has dark brown palmar and plantar surfaces.

Colour in life: Dorsal surfaces coppery brown with two parallel mid-dorsal rows of large dark brown spots ( Figs 6 , 12 ). Dorsolateral stripes white to pale yellow. Sides dark brown to jet black with white or pale yellow spotting and white or pale yellow lateral stripe extending from occiput to hind limbs. Coloration of sides becomes gradually lighter ventrally from lateral stripes. Chin pale blue. Chest, abdomen, precloacal region, thighs and base of tail range from pale blue (BPBM 40335) through light lime green to bright lemon yellow. Yellow coloration more prominent in adult males.

Etymology: The Latin adjectival suffix –ensis denotes belonging to a place and is used in reference to the Huon Peninsula, Papua New Guinea, where the type series was collected.

Distribution: Known only from 1600–2690 m a.s.l. in the Finisterre Range, Madang Province and the Saruwaged Range, Morobe Province, both on the Huon Peninsula, Papua New Guinea. It is presumed endemic to the Huon Peninsula, where it is the only member of Lobulia present. Lobulia huonensis appears to be sympatric with one species of Papuascincus (lineage I), although Lo. huonensis is seemingly more common at higher elevations (most specimens collected> 2200 m a.s.l.), whereas Papuascincus sp. is more common at lower elevations (most specimens collected <2200 m a.s.l.).

Natural history: All animals were collected while basking on old tree stumps and logs within 2 m of the ground along walking tracks through highly degraded lower montane and montane forest or anthropogenic grassland, mostly between Teptep Station (2200 m) and Kawang Bagu Pass at around 3000 m on a track leading to Bumbu. Most of the forest along the track, particularly at lower elevations, had been replaced by tall anthropogenic grassland dominated by Saccharum × edule Hassk. (pitpit), Saccharum robustum E.W.Brandes & Jeswiet ex Grassl and Miscanthus floridulus (Labill.) Warb. ex K.Schum. & Lauterb. There were also large expanses of shorter grasses such as Themeda triandra Fossk. , Ischaemum polystachyum J.Presl and Imperata sp. Remnant trees included Pandanus sp. , Caldcluvia sp. and Saurauia spp. There was fairly intact mossy forest at higher elevations (> 2500 m) dominated by Nothofagus sp. , with a ground flora fairly typical of montane New Guinea that included as aspect dominants a variety of species of shrubs in the genera Rhododendron , Coprosma and Tasmannia , and an impressively robust ground moss, Dawsonia sp.

In much of New Guinea, timberline occurs at around 2800–3000 m. In the Finisterre Mountains, mossy forest extends to around 3200 m or higher. This was in line with our overall impression that the vegetation zones around Teptep were shifted upwards by 200–300 m compared to the rest of New Guinea. This may, at least in part, explain the occurrence of Lo. huonensis to nearly 2700 m; Lo. fortis and Lo. elegans , which are ecologically similar and occur in the central ranges, do not generally occur above 2400 m.

Like the two aforementioned species, Lo. huonensis is heliothermic and is exclusively found on tree stumps and logs. However, it is often found close to the ground, unlike Lo. fortis and Lo. elegans , which generally occur from 2–3 m above the ground. But like these species, Lo. huonensis is mainly active in the morning, when the first sun reaches its habitat. It is common.

Lobulia huonensis is sympatric with at least two other species of skinks: a ground-dwelling species of Papuascincus and the arboreal Pr. flavipes . A terrestrial colubrid snake, Tropidonophis sp. , occurs to 2500 m. There are only two sympatric species of nocturnal, scansorial frogs above 2200 m: Choerophryne sp. and Cophixalus sp. Zweifel (1980) has commented on the relatively low diversity of montane frogs on the Huon Peninsula, attributing this to the geological youth of the Saruwaged and Finisterre mountain ranges.

Reproduction: Viviparous. Only a single gravid female was collected, with two embryos, but litter size is presumably variable in this species, as in other members of the genus.

Conservation status: The species appears locally abundant at the type locality although the population trend is unknown. Based on the sampled populations, Lo. huonensis has an extent of occurrence of 100 km 2 and an area of occupancy of 16 km 2 (based on occupation of 4 km 2 cells; both calculated using http:// geocat.kew.org/). However, its distribution almost certainly encompasses more populations throughout the Huon Peninsula at suitable elevations, and the true area of occupancy and extent of occurrence are likely much larger than estimated here. The type locality is approximately 3 km from a protected area, the YUS Conservation Area. Since it is locally abundant, with no immediate direct threats to the species or indirect threats to its habitat or location, and because it likely occurs over a wide distribution range encompassing at least one protected area, we recommend assigning a status of Least Concern to Lo. huonensis , although its true distribution extent needs to be confirmed through further surveys in the Huon Peninsula.

Figures

Figure 6. Pictures in life of (A) Lobulia brongersmai (BPBM 34733); (B) Lobulia elegans (BPBM 18692); (C) Lobulia fortis (paratype; BPBM 41130); (D) Lobulia huonensis (holotype; BPBM 40322); (E) Lobulia lobulus (BPBM 47837); (F) Lobulia marmorata (holotype; BPBM 34150). Images A, B, F by Fred Kraus, images C–E by Allen Allison.

Figure 11. Lobulia huonensis holotype (BPBM 40322), in (A) dorsal view, (B) ventral view, (C) lateral view of head, (D) dorsal view of head and (E) ventral view of head. Images by Alex Slavenko.

Figure 12. Lobulia huonensis holotype (BPBM 40322), in life, in (A) dorsal view and (B) ventral view. Images by Allen Allison.