Gigantomorpha sayapensis Ng & Likhitrakarn, 2025

Gigantomorpha sayapensis Ng & Likhitrakarn sp. nov.

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Figs 8–10 View Fig View Fig View Fig

Diagnosis

Differs from all known congeners by the gonopod tip with a small bifid structure, lacking the distinct branching observed in other species. This characteristic appears to be particularly similar to both G. mutilata and G. transmontana . However, the new species differs in having a thicker, apically expanding solenophore (i.e., the solenophore becomes slightly wider towards the apex) ( Figs 9B–C View Fig , 10A–C View Fig ) (vs long, slender and tapering in all the other species).

Etymology

To emphasise the type locality, adjective in feminine gender.

Material examined

Holotype

MALAYSIA • ♂; Borneo, Sabah, Kota Belud, Kinabalu Park , Sayap Substation ; 6°09′8.9″ N, 116°34′8.5″ E; ca 1071 m a.s.l.; 10 Mar. 2023; T.H. Ng, F. Anthony and D. Bantason leg.; SP 14835 .

GoogleMaps

Description

Length of holotype 35.3 mm, width of midbody pro- and metazona of holotype, 2.5 and 5.1 mm, respectively.

Colouration of living animal castaneous brown ( Fig. 8A View Fig ); with contrasting pale pinkish paraterga, antennae dark brown, venter and legs yellowish brown; colouration of alcohol material after seven months of preservation a little faded to red-brown castaneous; paraterga pale pinkish to pale red, antennae brown to light brown, venter and legs light brown to light yellowish ( Fig. 8B–J View Fig ).

Clypeolabral region and vertex sparsely setose, epicranial suture distinct.Antennae rather short ( Fig. 8A– C View Fig ), reaching body ring 4 when stretched dorsally. In length, antennomere 3>2= 4>5>6>> 1=7. Interantennal isthmus ca 0.6 times diameter of antennal socket ( Fig. 8B View Fig ). In width, head <ring 3<4<collum <ring 2<5<6<7–16 ( Fig. 8B 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. 8C View Fig ).

Tegument rather smooth and shining, prozona delicately shagreened, metaterga smooth and leathery, posterior halves faintly rugulose, surface below paraterga microgranulate ( Fig. 8A–F, H View Fig ). Postcollum metaterga each with two transverse rows of setae: 2+ 2 in anterior and 3+ 3 in posterior row, setae in posterior row mostly abraded and borne on minute knobs or oblong wrinkles ( Fig. 8B–F, H View Fig ). Tergal setae rather short, strong, slender, about 1/5 metatergal length. Axial line traceable both on pro- and metazona. Paraterga strongly developed ( Fig. 8A–F, H View Fig ), subhorizontal, slightly upturned posteriorly, always lying high, at upper 1/3 midbody height, but remaining below dorsum; anterior edge broadly rounded and narrowly bordered, fused to callus; caudal corner almost completely to fully pointed, always extending past rear tergal margin, bent posteriad on rings 18 and 19; posterior edge oblique ( Fig. 8B, D, F View Fig ); paraterga thin blunt blades in lateral view, a little thicker only on pore-bearing rings ( Fig. 8E View Fig ). Calluses on paraterga delimited by a sulcus only dorsally, but on pore-bearing ring paraterga demarcated by sulci both dorsally and ventrally. Paraterga 2 broad, lateral edge with two small incisions at lateral edge ( Fig. 8B View Fig ), one in anterior 1/3, the other at posterior 1/3. Paraterga 3 and 4 each with an evident incision in anterior 1/3 and a small knob in posterior 1/3 ( Fig. 8B View Fig ). Lateral edge of paraterga of following rings with two small incisions, one in anterior 1/3, the other at midway, caudal incision in the pore-bearing rings smaller or gradually reduced in posterior rings ( Fig. 8D, F View Fig ). Ozopores evident, lateral, each lying in an ovoid groove at about 1/3 metatergal length in front of posterior edge of metaterga ( Fig. 8C, E, H View Fig ).

Transverse metatergal sulci usually distinct ( Fig. 8B, D, F View Fig ), slightly incomplete on rings 4 and 19, complete and clearly visible on metaterga 5–18, rather deep and wide, reaching the bases of paraterga, arcuate, faintly beaded at bottom. Stricture between pro- and metazona narrow, deep, beaded at bottom down to base of paraterga ( Fig. 8C–E View Fig ). Pleurosternal carinae complete crests on ring 2, thereafter broken into an anterior bulge and a caudal tooth, both increasingly reduced until ring 7, thereafter missing ( Fig. 8C, E, H View Fig ).

Epiproct ( Fig. 8F–H View Fig ) conical, flattened dorsoventrally, subtruncate, with two evident apical papillae directed caudally, both pointed at tip; pre-apical papillae small, but evident, lying close to tip. Hypoproct subtrapeziform ( Fig. 8G View Fig ), small setigerous knobs at caudal edge well-separated and evident.

Sterna sparsely setose, without modifications ( Fig. 8G View Fig ); cross-impressions shallow; a sparsely setose and 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. 8I–J View Fig ). A paramedian pair of small, but evident tubercles in front of gonopod aperture. Legs long and slender, midbody legs ca 1.3–1.5 times as long as body height ( Fig. 8A, C View Fig ); prefemora without modifications; tarsal brushes present until legs of ring 18.

Gonopods ( Figs 9–10 View Fig View Fig ) rather simple; coxa long and thick, subcylindrical, a little curved caudad, sparsely setose distoventrally ( Figs 9A–B View Fig , 10A–C View Fig ). Prefemoral part short, densely setose as usual, about 1/4 as long as femoral part + postfemoral part ( Fig. 10A–C View Fig ). Femoral part long and slender, expanded distad, slightly curved, postfemoral part demarcated by an oblique lateral sulcus ( Figs 9B–C, F View Fig , 10A, C View Fig ); seminal groove running entirely mesally along the femoral part, solenomere (sl) flagelliform, fully sheathed by solenophore (sph). Lamina medialis (lm) well developed, prominent and unciform, terminal tip clearly bifid, terminal lobe a little larger than subterminal one ( Figs 9A–D, E View Fig , 10B–C View Fig ). Lamina lateralis (ll) unciform, shorter than lamina medialis (lm), bifid, with two subequal lobes ( Figs 9 View Fig , 10B–C View Fig ).

Remarks

This species was collected from the ground, under a rotten branch, in a lower montane forest habitat on the western side of the Kinabalu Park complex ( Fig. 1C View Fig ).