Scutiger khumbu makalu, Hofmann & Ohler & Baniya & Dubois & Flecks & Jablonski & Schmidt & Dufresnes, 2025

Scutiger khumbu makalu subsp. nov.

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Figs 6, 9–10; Tables 1, 3; Supp. file 1J

Diagnosis

Scutiger khumbu makalu subsp. nov. can be distinguished from the nominotypical subspecies and other Scutiger taxa based on multiple nucleotide substitutions in mitochondrial COI, cytb, and 16S sequences, as well as private alleles at the nuclear genes bfib7 and ccnb2 (Supp. file 1D–I), but not at the nuclear gene rag1. Specifically in the barcoding gene COI, Scutiger khumbu makalu subsp. nov. is separated from the nominotypical subspecies and other currently recognized Scutiger species by two binary and four asymmetric molecular signature characters ( Table 1). Morphologically, this taxon closely resembles the nominotypical subspecies of Scutiger khumbu sp. nov. but it exhibits a relatively larger foot length and tubercles that are less densely covered with small, keratinized tips, which also do not appear as dark as in the nominotypical subspecies ( Fig. 6).

Etymology

The subspecific epithet ʻ makalu ʼ refers to the Makalu region in Nepal.

Type material

Holotype

NEPAL • ♂; Bhojpur District , Salpa Pokhari; 27°26′47″ N, 86°56′01″ E (WGS 84); 22 Jun. 2003; Thierry Deuve leg.; donated by Thierry Deuve; MNHN 2003.3041. GoogleMaps

Paratype

NEPAL • 1 ♂; same locality as for holotype; 22 Jun. 2003; Thierry Deuve leg.; donated by Thierry Deuve; MNHN 2003.3042 GoogleMaps .

Other specimens examined

NEPAL • 5 tadpoles; Sankhuwasabha District ; 27°38′ N, 87°13′ E (WGS 84); 3600 m a.s.l.; Jun. 1997; local residents leg.; NHME (uncatalogued, field numbers JS1405.23–27) GoogleMaps .

Description (holotype)

Adult male, well preserved ( Fig. 10). Measurements are provided in Table 3. SVL = 47.9 mm.

HEAD. Large and flat, wider than long (HW/HL = 1.22); snout short and rounded; canthus rostralis distinct; nostril dorsolateral, just below canthal, midway between the tip of snout and eye (NSD/END = 1.00); loreal region slightly concave; eye relatively large (ED/HL = 0.37); internarial surface flat (IND = 5.10); pupil vertical; interorbital space flat; tympanum and tympanic ring absent; tongue oval; choanae small, visible when viewed from below; vomerine and maxillary teeth absent; vocal sac absent; supratympanic fold distinct, extending from posterior corner of eye to supra-axillary region, associated with parotoid glands.

FORELIMBS. Robust; forearm of median length (FAL/SVL = 0.28) and longer than hand (HAL/SVL = 0.26), without spines; fingers slender, free of dermal fringes or web; all fingertips rounded, not dilated; relative finger lengths: 3> 4> 2> 1; subarticular tubercles absent; inner metacarpal tubercle flat and large; outer metacarpal tubercle large, nearly round, and flat; black nuptial spines on dorsal and lateral surface of first and second fingers, and on inner side of third finger.

HINDLIMBS. Robust, moderately long (TIBL/SVL = 0.41; FEL/TIBL = 1.10), heels are not in contact when folded at right angles to the body (see also Fig. 10); foot longer than shank; tips of toes round; toes not webbed, relative lengths 4> 3> 5> 2> 1; subarticular tubercles absent; moderately large inner metatarsal tubercle, outer metatarsal tubercle absent.

SKIN. Body dorsally and laterally with distinct tubercles in preservative, each tubercle with one large keratinized spine in the center ( Fig. 6B), surrounded by small, keratinized dark brown or blackish tips; small scattered spines on upper and lower mandibles; dorsal surface of forehead and surfaces of lower arm relatively smooth; tubercles with spines present below and on supratympanic fold; upper arms and legs with tubercles, most of them with spines; throat and belly surface smooth; a pair of pectoral glands and a pair of axillary glands present on chest, connected, pectoral glands larger than axillary, all covered by small black spines.

Coloration

In preservative, dorsal surfaces gray, ventral surfaces grayish white.

Distribution

This subspecies is known from cloud forests in high-montane areas in the Makalu region in Nepal at altitudes between ca 3000 and 3600 m a.s.l., specifically in the Bhojpur District (Salpa Pokhari), and in the Sankhuwasabha district.

Taxonomic remarks

Scutiger khumbu makalu subsp. nov. was previously identified as a distinct phylogeographic lineage by Hofmann et al. (2017) based on molecular data of a few samples. It is characterized by high genetic divergence in the COI (8.8%), cytb (6.3%), and 16S (2.5%) genes, distinct alleles at the nuclear bfib7 and ccnb2 genes, and shared alleles at the rag-1 gene, with the nominotypical subspecies of Scutiger khumbu sp. nov., to which it is allopatric and lacks a clear morphological differentiation. The divergence being lower than in most Scutiger species, it is therefore described as a new subspecies of Scutiger khumbu sp. nov.

Remarks on larvae

Five tadpoles of Scutiger khumbu makalu subsp. nov. at different stages ranging from 26 to 29 ( Gosner 1960) ( Fig. 9); LTRF: 3(2–3)/3(1–2) or 3(2–3)/4(1–3).