Gigantomorpha alabensis Ng & Likhitrakarn, 2025

Gigantomorpha alabensis Ng & Likhitrakarn sp. nov.

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Figs 2–4 View Fig View Fig View Fig

Diagnosis

This new species closely resembles G. sayapensis sp. nov., but differs in the pleurosternal carinae in males present until ring 7 (vs 4), shorter male legs, ca 1.3–1.5 times as long as midbody height (vs 1.5– 1.7 times), and tarsal brushes in males present until ring 18 (vs ring 16), coupled with the gonopodal lamina medialis (lm) tip bifid, with a deep and evident incision (vs a single subtruncate tip).

Etymology

To emphasise the type locality, adjective in feminine gender.

Material examined

Holotype

MALAYSIA • ♂; Borneo, Sabah, Tambunan, Crocker Range Park , Gunung Alab Substation ; 5°49′17.6″ N, 116°20′29.4″ E; ca 1904 m a.s.l.; 19 Mar. 2023; T.H. Ng, T.S. Liew and F. Anthony leg.; SP 14836 .

GoogleMaps

Description

Length of holotype 28.5 mm, width of midbody pro- and metazona of holotype, 2.2 and 4.8 mm, respectively.

Colouration of alcohol material after seven months of preservation castaneous with a pattern of contrasting pale pinkish to whitish paraterga and epiproct, antennae brown to light yellowish, venter brownish to light brown, and legs light brown to light yellowish ( Fig. 2A–I View Fig ).

Clypeolabral region and vertex densely setose, epicranial suture distinct.Antennae rather short ( Fig. 2B View Fig ), reaching body ring 4 when stretched dorsally. In width, head <ring 3<collum <ring 4<2<5<6 <7–16 ( Fig. 2A View Fig ), thereafter body gently and gradually tapering. Collum with three transverse rows of strong setae: 3+3 anterior, 2+2 intermediate, and 4+4 posterior; caudal corner very broadly rounded, paraterga declined ventrad, not produced past rear tergal margin ( Fig. 2A–B View Fig ).

Tegument rather smooth and shining, prozona delicately shagreened, metaterga smooth and leathery, posterior halves faintly rugulose, surface below paraterga microgranulate ( Fig. 2A–F View Fig ). Postcollum metaterga each with two transverse rows of setae: 2+ 2 in anterior, 3(4)+3(4) in posterior row, setae in posterior row mostly abraded and borne on minute knobs or oblong wrinkles. Tergal setae rather short, strong, slender, about 1/4 metatergal length. Axial line traceable both on pro- and metazona. Paraterga strongly developed ( Fig. 2A–G View Fig ), subhorizontal, slightly upturned posteriorly, always lying high, at upper 1/3 midbody height, but remaining below dorsum; anterior edge on rings 2–4 each broadly rounded and narrowly bordered, fused to callus; following rings slightly rounded and oblique laterally ( Fig. 2A View Fig ); caudal corner almost completely to fully pointed, always extending past rear tergal margin, bent posteriad on rings 16–19 ( Fig. 2E–G View Fig ); posterior edge oblique ( Fig. 2A, C, F View Fig ); paraterga thin blunt blades in lateral view, a little thicker only on pore-bearing rings ( Fig. 2D View Fig ). Calluses on paraterga delimited by a sulcus only dorsally, but on pore-bearing ring paraterga with sulci both dorsally and ventrally. Paraterga 2–4 broad, lateral edge of each with two small incisions at lateral edge ( Fig. 2A View Fig ), one in anterior 1/3, the other in posterior 1/3. Lateral edge of paraterga of following rings with two small incisions, one larger and one smaller, but evident incisions in anterior 1/3 ( Fig. 2A, C, F View Fig ). Ozopores evident, lateral, lying in an ovoid groove at about 1/3 of metatergal length in front of posterior edge of metaterga ( Fig. 2B, D–E View Fig ).

Transverse metatergal sulci usually distinct ( Fig. 2A, C, F View Fig ), slightly incomplete on ring 19, complete and clearly visible on metaterga 5–18, deep and narrow, reaching the bases of paraterga, line-shape, ribbed at bottom. Stricture between pro- and metazona narrow, deep, beaded at bottom down to base of paraterga ( Fig. 2A, C, F View Fig ). Pleurosternal carinae complete crests bulged anteriorly and with a sharp caudal tooth on ring 2, thereafter only a sharp caudal tooth on ring 3, a small denticle on ring 4, thereafter missing ( Fig. 2B View Fig ).

Epiproct ( Fig. 2E–G View Fig ) conical, flattened dorsoventrally, subtruncate, with two evident apical papillae directed caudally, both pointed; pre-apical papillae small, but evident, lying close to tip. Hypoproct subtrapeziform ( Fig. 2G View Fig ), small setigerous knobs at caudal edge well-separated and evident.

Sterna separsely setose, without modifications; cross-impressions rather shallow; a sparsely setose, transverse lobe bearing a paramedian pair of evident, basally contiguous cones between male coxae 4 and a pair of small, separated cones near each coxa 5 ( Fig. 2H–I View Fig ). A paramedian pair of small, but evident tubercles in front of gonopod aperture. Legs long and slender, midbody ones ca 1.5–1.7 times as long as body height; prefemora without modifications; tarsal brushes present until legs of ring 16.

Gonopods ( Figs 3–4 View Fig View Fig ) simple; coxa long and thick, subcylindrical, a little curved caudad, sparsely setose distoventrally ( Figs 3A–B, E View Fig , 4A–B View Fig ). Prefemoral part short, densely setose as usual, about 1/4 as long as femoral part + postfemoral part ( Fig. 3A–B View Fig ). Femoral part long and slender, expanded distad, slightly curved, postfemoral part demarcated by an oblique lateral sulcus ( Figs 3A–D, F View Fig , 4A–B View Fig ); seminal groove running entirely mesally along the femoral part, solenomere (sl) flagelliform, fully sheathed by solenophore (sph). Lamina medialis (lm) well developed, elevated, prominent, stout, slightly expanded apically, tip bifid with a deep and evident incision ( Figs 3A–D View Fig , 4A View Fig ), terminal lobe with minute denticles at ventral margin ( Fig. 3A, C, F View Fig ). Lamina lateralis (ll) shorter than lamina medialis (lm), subtruncate at tip ( Figs 3A, C View Fig , 4B View Fig ).

Remarks

This species was found at the Gunung Alab Substation ( Fig. 1C View Fig ), inside a small building which houses the office and guesthouse, adjacent to forest trails, and together with Orangutana koropungoi Ng & Likhitrakarn sp. nov.