Microcyba magna, Tanasevitch, 2023

Tanasevitch, Andrei V., 2023, Survey of the Ethiopian linyphiid spider fauna. I. Subfamily Erigoninae (Arachnida, Araneae, Linyphiidae), Zootaxa 5346 (4), pp. 420-442 : 427-430

Microcyba magna new species

Figs 5 , 6

Type material. Holotype: J ( ZMMU), ETHIOPIA, Addis-Ababa, Russian Embassy Area, 9.03491°N 38.78236°E, 2446 m a.s.l., grove with Eucalyptus , Juniperus , etc, bushes, tall grass, sifting litter and humus, 12.X.2022, A. Tanasevitch leg. [Eth006]. Paratypes: 4J, 23♀ ( ZMMU), 3J, 9♀ ( MHNG), same date and locality, together with holotype; 2J, 4♀ ( ZMMU), Addis-Ababa, Russian Embassy Area, 9.037774°N 38.785607°E, 2488 m a.s.l., sifting litter and humus under single-standing broad-leaved tree, 07.X.2022, A. Tanasevitch leg. [Eth001]; 6♀ ( ZMMU), same area, 9.03593°N 38.78579°E, 2478 m a.s.l., Juniperus , Acacia , Eucalyptus , etc, bushes, sifting litter and humus, 07.X.2022, A. Tanasevitch leg. [Eth002]; 3J, 13♀ ( ZMMU), same area, 9.03638°N 38.78541°E, 2470 m a.s.l., Eucalyptus grove with Juniperus , etc, bushes, sifting litter and humus, 08.X.2022, A. Tanasevitch leg. [Eth003]; 11♀ ( ZMMU), same area, 9.0350476°N 38.7836601°E, 2467 m a.s.l., Eucalyptus grove with Juniperus , Acacia , etc, bushes, sifting litter and humus, 10.X.2022, A. Tanasevitch leg. [Eth004]; 9J 42♀ ( ZMMU), same area, 9.03617°N 38.78549°E, 2467 m a.s.l., grove with Juniperus , Eucalyptus , palm trees, etc, bushes, sifting litter and humus, 11.X.2022, A. Tanasevitch leg. [Eth005]; 10♀ ( ZMMU), same area, 9.03468°N 38.78379°E, 2454 m a.s.l., Eucalyptus grove with sporadic Juniperus , Acacia , etc, bushes, sifting litter and humus, 09.XI.2022, A. Tanasevitch leg. [Eth023]; 1J, 4♀ ( ZMMU), Oromia Region, 67 air-km E of Addis-Ababa, 5 air-km NNE from Ginchi, Chilimo State Forest, spring valley near road, 9.07061°N 38.15804°E, 2584 m a.s.l., Podocarpus falcatus forest with Juniperus procera , Prunus africana , Olea europaea , Hagenia abyssinica , Apodytes dimidiata , Ficus spp. , Erythrina brucei , etc, grass, sifting litter and humus, 15.X.2022, A. Tanasevitch leg. [Eth008]; 2♀ ( ZMMU), Oromia Region, Suba Menagesha N.P., 8.963990°N 38.546910°E, 2530 m a.s.l., Juniperus procera forest with Acacia melanoxylon , etc, bushes, grass, sifting litter and humus, 11.XI.2022, A. Tanasevitch leg. [Eth025].

Etymology. The specific epithet is the Latin adjective meaning “large”, referring to the largest body size among the Microcyba species.

Diagnosis. The new species seems to be a largest among the presently known representatives. Besides this, the male is diagnosed by the presence of sulci on the carapace, a massive and strongly sclerotized paracymbium, the characteristic shapes of the palpal tibial outgrowths, the peculiar structure of the embolic division, as well as by the shape of the epigynum in the female. The male of the new species seems to be especially similar to M. tridentata Holm, 1962 , known from Kenya and Uganda ( Holm 1962), but it differs well by the larger size (1.75 vs 1.35), the presence of sulci, the length and shapes of the palpal tibial outgrowths, the much wider radix, as well as by the expanded base of the embolus. The female seems to be is particularly similar to M. affinis , known from Uganda ( Holm 1962), but, in addition to the larger size (1.70 vs 1.30), its epigynum is more strongly elongated, with widely spaced receptacles.

Description. Male (Paratype from Eth006). Total length 1.75. Carapace modified, as shown in Figs 5A–C , 0.80 long, 0.65 wide, reddish brown to dark brown, with radial stripes, finely reticulate, high in lateral view, with a sharp slope at back. Clypeus slightly sloping, bearing a group of short spines. Sulci presense, very small. Eyes normal, not enlarged. Chelicerae 0.25 long, a mastidion absent. Legs pale brown to brown. Leg I 2.25 long (0.59 + 0.20 + 0.53 + 0.44 + 0.29), IV 2.03 long (0.60 + 0.17 + 0.54 + 0.42 + 0.30). Chaetotaxy 1.1.1.1, spines about 1–1.5 as long as a diameter of corresponding leg segment. Metatarsi I–III with a trichobothrium each. TmI 0.38. Palp ( Figs 6A–D ): Tibia with two outgrowths apically: a wide and narrow ones, situated on prolateral and retrolateral side, respectively. Paracymbium large, massive, L-shaped. Distal suprategular apophysis relatively long and wide, distally rounded, with a small and sharp tooth at middle. Median membrane short and wide. Radix wide proximally, narrowed at middle, its distal part black, curved, vague in shape; embolus short. Opisthosoma 0.95 long, 0.75 wide, grey ( Fig. 5A ).

Female (Paratype from Eth006). Total length 1.70. Carapace unmodified as shown in Figs 5D, E , 0.68 long, 0.55 wide, high in lateral view, brown to dark brown, with radial stripes, clypeus high, vertical. Chelicerae 0.33 long. Legs pale brown to brown. Leg I 1.64 long (0.49 + 0.17 + 0.39 + 0.30 + 0.29), IV 1.73 long (0.53 + 0.18 + 0.42 + 0.33 + 0.27). Chaetotaxy 1.1.1.1, spines about as long as diameter of corresponding leg segment. Metatarsi I–III with a trichobothrium each. TmI 0.45. Opistosoma 1.15 long, 0.95 wide, grey ( Fig. 5D ). Epigynum, as in Figs 5F, G , 6F, G , well-sclerotized, slightly protruded, ventral plate tapering and wedge-shaped posteriorly, dorsal plate broadened proximally, conical distally.

Distribution. Known only from the mountains of Oromia Region, Ethiopia, ranging from 2446 to 2584 m a.s.l.

Figures

FIGURE 5. Photographs of male (A–C) and female (D–G) of Microcyba magna n. sp., paratypes from Eth001. A, D, habitus, dorsal view; B, prosoma, lateral view; C, E, habitus, frontal view; F, opisthosoma, ventral view; G, epigynum, ventral view. Scale bars: A–F, 0.5mm; G, 0.1mm.

FIGURE 6. Details of male palpal structure (A–D) and female epigynum (E, F) of Microcyba magna n. sp., paratypes from Eth004. A, B, right palp, retrolateral and prolateral view, respectively; C, tibia, dorsal view; D, distal suprategular apophysis and embolic division, prolateral view; E, F, epigynum, ventral and dorsal view, respectively. Scale bar: 0.1mm.