Metabiantes elongatus, Mamani & Jocqué & Pérez-González, 2025

Mamani, Vanesa, Jocqué, Merlijn & Pérez-González, Abel, 2025, Notes on African Biantinae with sexual dimorphism in leg II: five new Metabiantes species and redescription of Clinobiantes paradoxus (Opiliones: Laniatores: Biantidae), European Journal of Taxonomy 1006, pp. 1-58 : 11-21

publication ID	https://doi.org/10.5852/ejt.2025.1006.2989
publication LSID	lsid:zoobank.org:pub:E4FAF05B-5420-42B0-AB8D-5870FD3E370A
DOI	https://doi.org/10.5281/zenodo.16745715
persistent identifier	https://treatment.plazi.org/id/03C2879B-FFE4-FFA6-4421-A41460D1F3D9
treatment provided by	Plazi
scientific name	Metabiantes elongatus
status	sp. nov.

Treatment

Metabiantes elongatus sp. nov.

urn:lsid:zoobank.org:act:CCA055CD-6549-420A-BD70-415692EE1280

Figs 7–14 View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig ; Table 2

Diagnosis

Metabiantes elongatus sp. nov. differs from the rest of the species of the genus (except M. serratus sp. nov., M. litoralis , and M. zuluanus ) by the following combination of characteristics: presence of two tubercles on mesotergal areas III–V ( Figs 7A View Fig , 8A View Fig , 13A View Fig ) and, in males, having a slender femur II ( Figs 10A View Fig , 14B, D View Fig ) and metatarsus II with tubercles on the ventral region ( Figs 10E View Fig , 14H View Fig ). Metabiantes elongatus and M. serratus share a remarkably similar male genital morphology but M. elongatus can be easily differentiated from M. serratus in lacking tubercles on free tergites I–II ( Fig. 7C View Fig vs Figs 33C View Fig , 34C View Fig ) and in possessing a thinner femur II ( Figs 10A View Fig , 14B, D View Fig vs Figs 36A–B View Fig , 39B, D View Fig ), unswollen tibia ( Figs 10C View Fig , 14F View Fig vs Figs 36C View Fig , 39F View Fig ), and unswollen metatarsus of leg II ( Figs 10E View Fig , 14H View Fig vs Figs 36E View Fig , 39H View Fig ). Additionally, M. elongatus lacks a pronounced constriction at astragalus-calcaneus junction in metatarsus of leg II as observed in M. serratus ( Fig. 10E–F View Fig vs Fig. 36E–F View Fig ). Metabiantes elongatus can be differentiated from M. litoralis by having granules on free tergites instead of the presence of a row of small tubercles in M. litoralis ( Fig. 7C View Fig vs Kauri 1961: fig. 33a–b). Males of Metabiantes elongatus have a non-enlarged trochanter II ( Fig. 7A View Fig ). In contrast, males of M. zuluanus exhibit a remarkably swollen trochanter II ( Lawrence 1937a: fig. 26a). Regarding male genital morphology, M. elongatus has a penis with a deeper U-shaped cleft of lamina apicalis, wider titillators, and remarkably smaller basal setae, easily differentiated from the penis of M. litoralis and M. zuluanus with a shallow cleft, narrow titillators, and bigger basal setae ( Figs 11B–D View Fig , 12A–C View Fig vs Kauri 1961: figs 22a–b, 34a–b).

Etymology

The species epithet is derived from the Latin word ‘ longatus ’, meaning ‘elongate’ and refers to the elongated femur II in males of this species.

Type material

Holotype

CONGO • ♂; Bas-Congo, Mayombe, Luki Forest Reserve ; 5.63333° S, 13.06667° E; 12 Nov. 2006; D. De Bakker and J.P. Michiels leg.; primary rainforest; fogging; RMCA, BE _ RMCA _ARA. Opi. 219865. GoogleMaps

Paratypes

CONGO • 1 ♂, 1 ♀; same data as for holotype; RMCA, BE _ RMCA _ARA.Opi.247662 GoogleMaps • 1 ♂ (SEM voucher); same data as for holotype; MACN-Ar 45425 GoogleMaps • 1 ♂ (SEM voucher); same data as for holotype; MACN-Ar 45430 GoogleMaps • 9 ♂♂ (1 photo voucher), 13 ♀♀ (1 photo voucher, 2 SEM vouchers); same data as for holotype; MACN-Ar 45440 GoogleMaps • 9 ♂♂, 6 ♀♀; same data as for holotype; 13 Nov. 2006; RMCA, BE _ RMCA _ARA.Opi.219866 GoogleMaps • 10 ♂♂, 16 ♀♀; same data as for holotype; 5 Nov. 2006; RMCA, BE _ RMCA _ARA.Opi.219858 GoogleMaps .

Description

Male (holotype, BE_RMCA_ARA.Opi.219865)

BODY MEASUREMENTS. Total body length 1.95, carapace length 0.66, scutum magnum length 1.84, carapace maximum width 1.08, abdominal scutum maximum width 1.62. Appendage measurements in Table 2.

DORSUM. Outline slightly hourglass-shaped with Eta (η) shape, with a very slight constriction located at sulcus I level ( Figs 7A View Fig , 8A View Fig ). Carapace with scattered granules, wider than long; anterior border slightly convex and unarmed ( Figs 7A View Fig , 8A View Fig ). Cheliceral sockets not marked ( Fig. 8A View Fig ). Eyes separated near sulcus I; interocular area with scattered granules ( Figs 7A, C View Fig , 8A, C View Fig ). Carapace in lateral view straight at anterior region and slightly higher posteriorly ( Figs 7C View Fig , 8C View Fig ). Sulcus I deep and complete, medially slightly curved toward the posterior body region ( Fig. 8A View Fig ). Mesotergal areas I–IV granulated and well-defined, with sulci II–IV marked but shallower than sulcus I; medially sulcus II slightly curved to the anterior body region; sulci III–V straight ( Fig. 8A View Fig ). Mesotergal areas III–IV medially with two conical and pointed setiferous tubercles ( Figs 7A View Fig , 8A View Fig ). Mesotergal area V with two irregular rows of granules and four medial tubercles in the posterior margin ( Fig. 8A View Fig ). Lateral margins with a row of granules ( Figs 7A View Fig , 8A View Fig ). Ozopore with an oval and narrow orifice with a descending channel that extends toward the ventroposterior region ( Fig. 8C View Fig ). Free tergites granulated ( Fig. 7C View Fig ).

VENTER. Coxa I with few, small, medial setiferous granules; coxa II incrassated, slightly smaller than coxa IV ( Figs 7B View Fig , 8B View Fig ); anteroposterior borders of coxa III with a row of strong granules connecting with coxae II and IV, respectively ( Fig. 8B View Fig ). Posterior border of spiracular area, free sternites I–V with a row of granules; anal operculum granulated ( Fig. 8B View Fig ) Spiracles not concealed ( Fig. 8B View Fig ).

CHELICERA. Basichelicerite unarmed with slightly marked bulla ( Fig. 9G View Fig ). Cheliceral hand with sparse setae ( Fig. 9G–H View Fig ). Fixed finger with spaced, triangular-shaped teeth; movable finger with a row of small, rounded teeth ( Fig. 9H View Fig ).

PEDIPALP. Coxa elongated (i.e., remarkably longer than trochanter), proximally with three granules – one dorsoectal, one ectal ( Fig. 8A View Fig ), and one ventroectal ( Fig. 8B View Fig ). Trochanter with one small ventroectal setiferous granule ( Fig. 8B View Fig ). Femur straight, proximally with a strong ventral narrowing followed by a small ventromesal spine ( Fig. 9A–B View Fig ); ventrally with scattered pores and surface texture with scales-like appearance ( Fig. 9B, D View Fig ). Patella elongated, club-shaped, and armed with a short mesodistal spine ( Fig. 9A View Fig ). Tibia with two ventroectal and two long ventromesal spines ( Fig. 9A, C View Fig ); tibia ventrally with scattered pores and scales-like surface ( Fig. 9E View Fig ). Tarsus with two ventromesal and two ventroectal spines; proximal spines longer than distal spines ( Fig. 9A, C View Fig ). Setae of spines with a basal portion smooth, then with scattered microtrichia ( Fig. 9C, E View Fig ); microtrichia with a wide base and rounded tip ( Fig. 9F View Fig ).

LEGS. Coxa II with a dorsal row of granules ( Fig. 8C View Fig ). Femur II elongated and slightly fusiform, swelling dorsally, slightly more pronounced, unarmed ( Figs 7C View Fig , 10A–B View Fig , 14D View Fig ). Tibia II elongated ventrally with small triangular-shaped tubercles ( Figs 10C–D View Fig , 14F View Fig ). Metatarsus II with elongated astragalus, armed with equidistant transverse rows of triangular-shaped tubercles ( Figs 10E–G View Fig , 14H View Fig ). Calcaneus occupies a reduced distal portion of the metatarsus; calcaneus with scattered long sensilla chaetica and trichomes distributed along all surfaces, with higher density on the ventral region; trichomes of variable length with a wider ovate-shaped base and pointed tip ( Fig. 10F, H View Fig ). Tarsi III–IV with a dense scopula. Tarsal formula: 3(2):5(4):5:5.

COLOR (specimen preserved in 80% ethanol). Body brown yellowish; anterior border and lateral margins of carapace, lateral area to eyes until anterolateral margin of mesotergal area I with brown reticulations ( Fig. 7A–C View Fig ). Appendages light brown yellowish; metatarsi and tarsi I–IV darker ( Figs 7A–C View Fig , 14B, D, F, H View Fig ).

MALE GENITALIA. Penis with clearly defined boundaries between pars basalis and pars distalis ( Fig. 11A View Fig ). Pars basalis basally thin, broadens medially, with distal constriction ( Fig. 11A View Fig ). Pars distalis swollen with maximum width at titillator level ( Figs 11B, D View Fig , 12A, C View Fig ); apical edge laminar (i.e., dorsoventrally flat) with a medial U-shaped cleft dividing it into two rounded halves ( Figs 11B, D View Fig , 12A, C View Fig ). Halves apically curved towards ventral side, less chitinous and irregularly deformed, probably signifying that could be inflated by hemolymph pressure ( Figs 11C–D View Fig , 12B–C, F View Fig ). Pars distalis with a slight distal depression in the ventromedial region ( Figs 11D View Fig , 12C, F View Fig ). Each side of pars distalis armed with short, conical microsetae irregularly arranged, extending basally from dorsolateral to ventrodistal region ( Figs 11B–D View Fig , 12A–C View Fig ). Capsula externa with two broad titillators that cover almost all the capsula interna ( Figs 11B View Fig , 12A View Fig ). Capsula interna with two complex conductors and one stylus, basally fused. Each conductor with two medial laminar folds apically, one short dorsal and one ventral longer, visible ventrally within the U-shaped cleft ( Figs 11B, D View Fig , 12A, C–G View Fig ). Ventral folds with apical edges in contact, waved, medially free edges dorsally ( Fig. 12D View Fig ) and ventrally folded, with a strongly curved and shorter subapical edge hoodshaped ( Fig. 12C, E, G View Fig ). Each conductor also bearing one broad lateral projection ( Fig. 11B, D View Fig ); stylus tubular, S-shaped in lateral view, with its free tip fully covered by conductors ( Fig. 11B–D View Fig ).

Female (paratype, MACN-Ar 45440)

BODY MEASUREMENTS. Total body length 1.97, carapace length 0.67, scutum magnum length 1.81, carapace maximum width 1.04, abdominal scutum maximum width 1.71. Appendage measurements in Table 2.

BODY. Resembles that of males in the armature of the scutum magnum ( Fig. 13A–B View Fig vs Figs 7A, C View Fig , 8A, C View Fig ). Leg II not dimorphic ( Fig. 14A View Fig ); femur II not swollen as in male ( Fig. 14A, C View Fig vs Fig. 14B, D View Fig ); tibia II thin as in male but without ventral tubercles ( Fig. 14E View Fig vs Fig. 14F View Fig ); metatarsus II thin and unarmed ( Fig. 14G View Fig vs Fig. 14H View Fig ). Tarsal formula 3(2):5(4):5:5.

FEMALE GENITALIA. Ovipositor cylindrical ( Fig. 13C View Fig ), distally bearing two lobes (furca) ( Fig. 13C–D, F View Fig ). Each furcal lobe with five long, pointed setae ( Fig. 13E View Fig ) – three dorsal and two ventral – resulting in a total of six setae on the dorsal region ( Fig. 13D View Fig ) and four on the ventral region ( Fig. 13F View Fig ). External surface of dorsal and ventral furcal lobes medially with several short, pointed projections, irregularly distributed ( Fig. 13D, F View Fig ). Receptacle chambers located near the base of the furcal groove ( Fig. 13D–F View Fig ).