Gasterapophus, Zhang & Lian & Zhang, 2015

Zhang, Chao, Lian, Wei-Guang & Zhang, Feng, 2015, Gasterapophus (Opiliones: Laniatores: Epedanidae), a new genus from Hainan Island, South China Sea, Raffles Bulletin of Zoology 63, pp. 97-109 : 98-99

Gasterapophus , new genus

Type species. Gasterapophus binatus , new species

Diagnosis. This new genus is noticeably distinct from other epedanids by the combination of (1) Stigmatic area of male with large armature; (2) body dorsally unarmed; (3) carapace with three tubercles on each side of front margin; (4) coxa IV widened conspicuously; (5) basichelicerite unarmed, disto-dorsally swollen; (6) segments of pedipalpus short and stout, never elongate; (7) femur of pedipalpus ventrally with four (IIii) setiferous tubercles, distally on medial side with one setiferous tubercle; (8) penis ventral plate, basal sac and cavity elongated.

Description. Male: dorsal scutum ( Figs. 1a , 4a ) pyriform in shape; widest portion of body at fifth scutal area. Carapace with three setiferous tubercles on each side of front margin. Surface of the dorsum almost smooth. Low oval ocularium, removed from anterior border of scutum. Dorsal hump on anterior margin. Opisthosomal region of scutum with five areas, the first area without a median longitudinal line. Scutal groove strongly convex; borders of all scutal areas slightly convex. Areas I–V unarmed, nearly smooth except a few much reduced granules; a row of microscopic granules across the posterior margin of the scutum and free tergites. A few scattered granules also on the anal plate.

Venter ( Figs. 1b , 3h , 4b ): all coxae and genital operculum with small granulations. Coxa I with rather coarse and numerous granulations. Coxa II with a few setiferous tubercles retrolaterally. Coxa III with prolateral and retrolateral rows of small humps. Coxa IV widened, with numerous setiferous tubercles prolaterally. Stigmatic area with at least one apophysis. Tracheal stigma clearly visible. Both tracheal stigmata with a row of tubercles laterally.

Chelicerae ( Figs. 1 c–e, 4c–e): proximal segment distodorsally visibly swollen, without any conspicuous armament. Second segment unarmed, only with hairs which are scattered mainly on the prodorsal surface. Fingers relatively short.

Pedipalpus ( Figs. 2f, g , 5g, h ): coxa dorsally with one stout setiferous tubercle, ventrally with one acute setiferous tubercle. Trochanter ventrally with one long and one short setiferous tubercle. Femur ventrally with four setiferous tubercles, distally on medial side with one setiferous tubercle. Patella with one setiferous tubercle disto-medially. Tibia with three medial (iII) and three ectal (iII) setiferous tubercles, the disto-ectal tubercle also with one accessory small tubercle. Tarsus with two medial and ectal enlarged setiferous tubercles. Tarsal claw longer than half of tarsus, strongly curved.

Legs ( Figs. 2 b–e, 5b–f): relatively short and stout. Trochanters I–IV unarmed above except for a few hair-tipped granules, more granules on the ventral surface. Trochanter IV conspicuously enlarged. Femora III–IV curved, especially femur IV. Femora I–III with fine hair-tipped granules which are arranged more or less in longitudinal series. Patella IV enlarged. Tibiae III–IV with conspicuously enlarged teeth ventro-distally. Base of metatarsus IV strongly curved. The remaining leg-segments unarmed, smooth, but with hairs. Tarsi III–IV with bare double claws, without scopulae. Tarsal formula: 4/7/5/6. Distitarsus I two-jointed and II three-jointed.

Penis ( Fig. 7 ): slender. Ventral plate well defined, spoonshaped. Cavity within the ventral plate, elongate. Glans entirely exposed in the cavity, nearly cylindrical, short. Base of glans connect to the basal sac and apex of glans with an opening. The opening of glans consists of ventral stylar lobe and dorsal stylar lobe. Stylus smooth, columnar and arising straight from glans, stylar lobe entirely surrounding the stylus. Basal sac irregular cylindrical, almost as long as cavity, partially sunken into truncus. Seminal canal visible.

Female ( Figs. 3 a–e, 6a–e): similar to the male but smaller and with abdomen more rounded posteriorly. Stigmatic area without any conspicuous apophysis.

Ovipositor ( Figs. 3f, g , 6f, g ): ventral surface with four setae and dorsal surface with six setae.

Sexual dimorphism. The most conspicuous sexual dimorphism is the presence of at least one large, robust apophysis on stigmatic area of male. The second most conspicuous dimorphic structure is found on the legs, especially tibiae III and IV, ventro-distally with enlarged teeth in males. Sternite and legs unarmed in female.

Habitat. Collected by leaf litter sieving in the tropical montane rainforest.

Etymology. The name derives from “gaster” (Greek) meaning belly and “apophusis” from the Greek meaning apophysis or outgrowth; referring to the apophysis of the male stigmatic area. Masculine.

Notes. Detailed illustrations of both the unexpanded and expanded penis from different views are very important to Laniatores taxonomy ( Martens, 1988). However, the fact is that the expanded conditions of penis are non-arbitrary. Although we succeed in expanding only a few specimens of Epedanidae with the method of Schwendinger & Martens (2002), we failed to expand every male specimen of this new genus with all methods available, e.g., Briggs (1974), Ubick & Briggs (1989) and Schwendinger & Martens (2002).

Figures

Fig. 1. Gasterapophus binatus, new species. Holotype male. a, b, body; a, dorsal view; b, ventral view (arrow indicates apophysis); c, d, left chelicerae; c, medial view; d, ectal view; e, cheliceral fingers, frontal view. Scale bars: a, b = 1 mm; c, d = 0.5 mm; e = 0.2 mm.

Fig. 4. Gasterapophus singulus, new species. Holotype male. a, b, body; a, dorsal view; b, ventral view (arrow indicates apophysis); c, d, left chelicerae; c, medial view; d, ectal view; e, cheliceral fingers, frontal view. Scale bars: a, b = 1 mm; c, d = 0.5 mm; e = 0.2 mm.

Fig. 3. Gasterapophus binatus, new species. Paratype, a–g, female (MHBU-Opi-HNQ0413); i, male (MHBU-Opi-HNQ0410); h, j–k, male (MHBU-Opi-HNQ0220). a, b, body; a, dorsal view; b, ventral view; c, cheliceral fingers, frontal view; d, left leg IV, retrolateral view; e, trochanter, femur and patella of left leg IV, prolateral view; f, g, ovipositor; f, dorsal view; g, ventral view; h, venter of coxa IV, stigmatic area and free sternites (arrow indicates apophysis); i, right pedipalpus, ectal view; j, right leg IV, prolateral view; k, patella and tibia of right leg IV, ventral view. Scale bars: a, b, d, e, h–k = 1 mm; f, g = 0.3 mm; c = 0.2 mm. Arrow indicates apophysis.

Fig. 2. Gasterapophus binatus, new species. Holotype male. a, body, lateral view (arrow indicates apophysis); b, left leg IV, prolateral view; c, patella, tibia, metatarsus and tarsus of right leg IV, retrolateral view; d, patella and tibia of right leg IV, ventral view; e, trochanter, femur and patella of right leg IV, prolateral view; f, left pedipalpus, mesal view; g, patella, tibia and tarsus of left pedipalpus, ectal view. Scale bars = 1 mm.

Fig. 5. Gasterapophus singulus, new species. Holotype male. a, body, lateral view (arrow indicates apophysis); b, left leg III, retrolateral view; c, patella, tibia, metatarsus and tarsus of left leg III, prolateral view; d–e, left leg IV; d, prolateral view; e, retrolateral view; f, patella and tibia of left leg IV, ventral view; g, left pedipalpus, mesal view; h, patella, tibia and tarsus of left pedipalpus, ectal view. Scale bars = 1 mm.

Fig. 7. Penis, a–d, Gasterapophus binatus, new species, a, entire penis, dorsal view; b–d, penis tip; b, dorsal view; c, lateral view; d, ventral view; e–h, Gasterapophus singulus, new species, e, entire penis, dorsal view; f–h, penis tip; f, dorsal view; g, lateral view; h, ventral view. Scale bars: a, e = 0.5 mm; b–d, f–h = 0.2 mm. BS–basal sac; C–cavity; DSL–dorsal stylar lobe; G–glans; LS–lateral setae; S–stylus; SC–seminal canal; SL–stylar lobe; VP–ventral plate; VS–ventral setae; VSL–ventral stylar lobe.

Fig. 6. Gasterapophus singulus, new species. Paratype, a–g, female (MHBU-Opi-HNQ0512); h–l, male (MHBU-Opi-HNQ0100). a–b, body; a, dorsal view; b, ventral view; c, cheliceral fingers, frontal view; d, left leg IV, retrolateral view; e, left leg III, prolateral view; f–g, ovipositor; f, dorsal view; g, ventral view; h, left leg III, retrolateral view; i, patella and tibia of left leg III, prolateral view; j, left leg IV, prolateral view; k–l, patella, tibia and metatarsus of left leg IV; k, ventral view; l, retrolateral view. Scale bars: a, b, d, e, h–l = 1 mm; c, f, g = 0.2 mm.