Orangutana koropungoi Ng & Likhitrakarn, 2025

Orangutana koropungoi Ng & Likhitrakarn sp. nov.

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Figs 11–13 View Fig View Fig View Fig

Diagnosis

This new species strongly resembles Orangutana setosa , with which it appears to share most of the gonopodal characteristics. However, the new species is distinguished from O. setosa by its considerably larger body measuring 35.3 mm in length (vs smaller, 11–12 mm), the colour pattern which is black to dark brown with contrasting lighter red-brown paraterga ( Fig. 11A–H View Fig ) (vs a uniformly pale yellowish brown to pale brown body), the longer antennae, in situ reaching body ring 4 ( Fig. 11A, C View Fig ) (vs only past body ring 2), as well as the pleurosternal carinae being with complete crests, each with an evident, sharp, caudal denticle produced past the rear tergal margin on rings 2–4, gradually decreasing in size until rings 7 (♂) or 4 (♀) ( Fig. 11C, E, H View Fig ) (vs completely absent), male sterna without modifications (vs male sterna show vestigial rounded knobs near the coxae starting with ring 8 onwards).

Etymology

“Koropungoi” is a vernacular name commonly used in the central Dusun language, which is spoken by people indigenous to the area around Gunung Alab and Mount Kinabalu, to denote a small millipede; noun in apposition.

Material examined

Holotype

MALAYSIA • ♂; Borneo, Sabah, Tambunan, Crocker Range Park , Gunung Alab Substation ; 5°49′17.6″ N, 116°20′29.4″ E; 1904 m a.s.l.; 19 Mar. 2023; T.H. Ng, T.S. Liew and F. Anthony leg.; BOR/MYR 44.

GoogleMaps

Paratypes

MALAYSIA • 1 ♀; Borneo, Sabah, Tambunan, Crocker Range Park , Gunung Alab Substation , along Minduk Sirung Trail ; 5°49′4.52″ N, 116°21′52″ E; 1918 m a.s.l.; 20 Mar. 2023; T.H. Ng, T.S. Liew and F. Anthony leg.; SP 14831 • 1 ♂; Borneo, Sabah, Ranau, Mesilau Nature Resort , Nepenthes Trail ; 6°02′45.4″ N, 116°35′49.1″ E; 1926 m a.s.l.; 26 Sep. 2023; T.H. Ng, F. Anthony, E.S.H. Quah, J. Dulipat, F.J. Chong, A. Joseph and C.L. Soo leg.; BOR/MYR 891 GoogleMaps • 1 ♂; same data as for preceding; SP 14833 GoogleMaps • 2 ♀♀; same data as for preceding; BOR/MYR 86, 88 GoogleMaps • 1 ♀; same data as for preceding; SP 14834 GoogleMaps • 2 ♀♀; Borneo, Sabah, Ranau, Mesilau Nature Resort , Tambang Gate ; 6°02′41.7″ N, 116°35′45.0″ E; 1922 m a.s.l.; 27 Sep. 2023; T.H. Ng, F. Anthony and F.J. Chong leg.; BOR/MYR 109, 110 GoogleMaps • 1 ♀; Borneo, Sabah, Tambunan, Crocker Range Park , Gunung Alab Substation , Nepenthes Trail ; 5°49′21.4″ N, 116°20′30.5″ E; ca 1900 m a.s.l.; 26 Mar. 2024; T.H. Ng and F. Anthony leg.; BOR/ MYR 137 GoogleMaps • 1 ♂; same data as for preceding; 27 Mar. 2024; BOR/MYR 138 GoogleMaps • 1 ♂; Borneo, Sabah, Tambunan, Crocker Range Park , Gunung Alab Substation , along road up to substation; 5°49′14.52″ N, 116°21′52″ E; ca 1800 m a.s.l.; 27 Mar. 2024; T.H. Ng and F. Anthony leg.; BOR/MYR 144 GoogleMaps .

GoogleMaps

Description

Length 30.6–32.5 mm (♂) or 26.8–34.8 mm (♀), width of midbody pro- and metazona 2.2–2.7 and 3.3–3.6 mm (♂) or 2.6–3.5 and 3.2–4.3 mm (♀), respectively.

Colouration of live animals blackish ( Fig. 11A View Fig ); with contrasting pale red paraterga, antennae brown, venter and legs yellowish brown; colouration of alcohol material after seven months of preservation faded to castaneous brown; paraterga yellowish brown to pallid, antennae light, venter and legs light brown to light yellowish ( Fig. 11B–J View Fig ).

Clypeolabral region and vertex sparsely setose, epicranial suture distinct. Antennae rather short ( Fig. 11A View Fig ), reaching body ring 4 (♂, ♀) when stretched dorsally. In length, antennomere 2>3= 4> 5> 6>> 1=7. Interantennal isthmus ca 0.6 times diameter of antennal socket ( Fig. 12A View Fig ). In width, head <collum <ring 3 <2<4 <5<6 <7–16 ( Fig. 11A–B 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. 11A, C View Fig ).

Tegument rather smooth and shining, moderately rugulose only near transverse sulcus, prozona delicately shagreened, metaterga smooth and leathery, posterior halves often rugulose, surface below paraterga microgranulate ( Fig. 11A–F, H View Fig ). Postcollum metaterga each with two uniform and transverse rows of setae: 2+ 2 in anterior, 3+ 3 in posterior row ( Fig. 11B–H View Fig ); setae in posterior row borne on knobs, which become increasingly crestlike towards the telson, these reaching the transverse sulcus, but then gradually decreasing in size towards ring 19 ( Fig. 11B, D, F View Fig ).

Tergal setae short, strong, slender, about 1/6 metatergal length. Axial line traceable both on pro- and metazona. Paraterga strongly developed ( Fig. 11A–F, H View Fig ), subhorizontal, slightly upturned posteriorly, always lying high, at upper 1/3 midbody height, but remaining below dorsum; anterior edge well-developed, mostly nearly straight and narrowly bordered, fused to callus ( Fig. 11B, D View Fig ); caudal corner of most paraterga very narrowly rounded, extending increasingly posterior tergal margin, slightly curved mesad on rings 14–19 ( Fig. 11F View Fig ), posterior edge oblique ( Fig. 11D, F View Fig ); paraterga very thin blunt blades in lateral view, a little thicker only on pore-bearing rings ( Fig. 11E View Fig ). Calluses on paraterga delimited by a sulcus only dorsally. Paraterga 2 broad, anterior edge convex, lateral edge with four small acute denticles. Following poreless rings each with two small incisions at lateral edge ( Fig. 11B View Fig ), one larger in anterior 1/3, the other smaller at posterior 1/3. Lateral edge of paraterga of following poreless rings with only one small incision near midway ( Fig. 11D View Fig ).

Ozopores evident, lateral, each lying in an ovoid groove at about1/3 metatergal length in front of posterior edge of metaterga ( Fig. 11C, E View Fig ). Transverse metatergal sulci usually distinct ( Fig. 11B, D, F View Fig ), slightly incomplete on rings 4 and 18, complete and clearly visible on metaterga 5–17, rather deep, reaching the bases of paraterga, ribbed at bottom. Stricture between pro- and metazona rather wide, deep, beaded at bottom down to base of paraterga ( Fig. 11C–E View Fig ). Pleurosternal carinae complete crests on rings 2–4, thereafter missing (♀) or broken into an anterior bulge and a caudal tooth, both increasingly reduced until ring 7, thereafter missing (♂) ( Fig. 11C, E, H View Fig ).

Epiproct ( Fig. 11F–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. 11G View Fig ), small setigerous knobs at caudal edge well-separated and evident.

Sterna sparsely setose, without modifications; cross-impressions shallow; a sparsely setose, transverse lobe bearing a paramedian pair of evident, basally contiguous cones between male coxae 4 ( Fig. 11I– J View Fig ). A paramedian pair of small, but evident tubercles in front of gonopod aperture. Legs long and slender, midbody legs ca 1.2–1.4 (♂) or 1.1–1.3 (♀) times as long as body height, prefemora without modifications, tarsal brushes present until legs 7.

Gonopods ( Figs 12–13 View Fig View Fig ) rather complex; coxa long and thick, subcylindrical, a little curved caudad, sparsely setose distoventrally ( Figs 12A–B View Fig , 14 View Fig ). Prefemoral part very short, densely setose about 1/5 as long as femoral part + postfemoral part ( Figs 12A–B View Fig , 14A–C View Fig ). Femoral part long and slender, slightly curved distad, postfemoral– part demarcated by a very faint and oblique lateral sulcus ( Figs 12B, E–F View Fig , 13C View Fig ); seminal groove running entirely mesally along the femoral part, solenomere (sl) flagelliform, fully sheathed by solenophore (sph). Solenophore hypertrophied composed of both well-developed lamina lateralis and lamina medialis. Lamina medialis (lm) well developed, thick and large, unciform, expanded apically, terminal tip clearly bifid, subterminal lobe smaller than terminal one, triangular in shape and pointed at tip; with a strong, sharp and denticulate process (d) at caudal edge ( Figs 12–13 View Fig View Fig ). Lamina lateralis (ll) thick and large, expanded apically, set lower than lamina medialis, both laminae supporting and sheathing most of solenomere ( Figs 12 View Fig , 13A, C–D View Fig ).

Remarks

This species was found at the Gunung Alab Substation ( Fig. 1C View Fig ), which primarily consists of mossy, montane forest habitats and experiences limited periods of sunlight and extensive fog cover throughout the day ( Majuakim & Anthony 2016). One individual was found inside a small building which houses the office and guesthouse, adjacent to forest trails, and together with Gigantomorpha alabensis sp. nov., while the others were revealed under rotten logs along forest trails or by the roadside. The species was also found in the eastern part of the Kinabalu Park complex, at Mesilau ( Fig. 1C View Fig ). Orangutana setosa , was reported from lowland areas in Sepilok, Sandakan, in eastern Sabah, approximately 180 km away from the type locality of the new species.