Afromygale rukanga, Zonstein, 2020

Zonstein, Sergei L., 2020, On Afromygale, a new mygalomorph spider genus from East Africa (Araneae: Pycnothelidae), Israel Journal of Entomology (Oxford, England) 50 (1), pp. 131-146 : 136-139

Afromygale rukanga n. sp.

( Figs 2–11)

LSID: urn:lsid:zoobank.org:act:8BB71496­EF44­4006­82C7­2BF0F460BA2F .

Etymology: The specific epithet is a toponym (a noun in apposition) referring to the type locality: the environs of the Rukanga village .

Diagnosis: The new species differs from Afromygale pinnipalpis n. sp. by a posteriorly narrower sternum, as well as by a number of the male characters: a relatively narrow (as broad as long) tegulum, an angularly ending embolic keel, and a longer distal portion of the embolus (vs. a posteriorly broader sternum, a broader than long tegulum, an obtuse­ending keel, and a shorter distal embolus; Figs 6, 9, 10 cf. Figs 15, 19, 20).

Description: Male (holotype). Total length 16.75. Habitus as in Fig. 2.

Colour in alcohol: carapace and most part of palps and legs medium ginger brown; eye tubercle brown to dark brown; chelicerae medium reddish brown; labium brownish orange; sternum, all coxae including maxillae, palpal tibia, cymbium, metatarsi and tarsi of legs I–IV yellowish brown; abdomen ventrally light brownish orange with pale brownish yellow spinnerets, dorsally light greyish brown with brown pattern consisting of narrow interrupted longitudinal median stripe and several pairs of lateral spots.

Cephalothorax dorsally and ventrally as in Figs 3 and 6, respectively. Carapace 6.62 long, 5.13 wide. Eye tubercle as in Fig. 4. Eye diameters and interdistances: AME 0.23 (0.31), ALE 0.32, PLE 0.26, PME 0.15, AME­AME 0.16 (0.08), AME­ ALE 0.14 (0.10), ALE­PLE 0.09, PLE­PME 0.05, PME­PME 0.62. Cheliceral furrow with 8 promarginal teeth and 20–22 minute mesobasal denticles ( Fig. 5). Male intercheliceral tumescence not reliably evident. Labium 0.82 long, 1.11 wide. Sternum 3.56 long, 2.52 wide.

Palp and leg structures. Tibia and metatarsus I as in Fig. 7. Spines (entire palp and tarsi I–III aspinose). Leg I: femur d1–1–1–1–1, pd0–1–1, rd0–1–1; patella p0–1; tibia p1(0)–1(0)–1, v1(0)–2(1)–2; metatarsus p1–1(0), v1–1–3. Leg II: femur d1–1–1–1, pd0–1–1, rd1(0)–1–1(0); patella p0–1; tibia p0–1–1, v2–2–3; metatarsus p1–1, v2–2–3. Leg III: femur d1–1–1–1, pd1–1–1, rd1–1–1; patella p1–1; tibia d1–1, p1–1–1(2), r1–1, v2–2–3; metatarsus d1–1–2, p1–1–1–1, r1–1–1, v2–2–3. Leg IV: femur d1–1–1–1–1–1(0), pd0, rd1–1–1; tibia p0–1–1–0, r0–1–1–0, v2–2–3; metatarsus d0–1–1–1, p1–1–1–1, r1–1–1, v2–2–3; tarsus r1. Trichobothria: 2 rows of 11–13 each on tibiae I–IV (7–8 in each row on palpal tibia), 15–18 on metatarsi, 12–14 on tarsi, 9 on cymbium. Scopula entire on tarsi I–III, distal and rudimentary on metatarsi I and II, absent on tarsus IV. PTC I–IV: outer and inner margins with 7–8 and 6–7 teeth, respectively. Unpaired claw on tarsi I–IV present, less reduced in size than in following species. Leg measurements:

Palp I II III IV

Femur 4.26 5.95 5.32 4.58 6.69

Patella 2.16 3.09 2.32 2.27 3.08

Tibia 2.91 4.02 3.80 3.11 5.03

Metatarsus – 4.41 4.08 4.57 6.37

Tarsus 1.12 2.60 2.56 2.74 3.12

Total 10.45 20.07 18.08 17.27 24.29

Distal segments of pedipalp and copulatory organ as in Fig. 8. Embolus tapering and slightly twisted, basoventrally with pterygoid membranous keel having longitudinal fold and acute distalmost edge ( Figs 9, 10).

Spinnerets ( Fig. 11). PMS: length 0.69, diameter 0.26. PLS: maximal diameter 0.79; length of basal, medial and apical segments 1.30, 0.72, 0.73; total length 2.75; apical segment triangular.

Female. Unknown.

Holotype: ♂ Kenya: Taita-Taveta County: Mt Kasigau 1–3 km SE Rukanga Village , 3°50'S 38°39'E, pitfall trap, 1–7.xii.2001, E. Selempo (RMCA­ARA­213003). The holotype is in a good condition.

Distribution: The species is known only from the type locality.

Ecology: According to the label data, the holotype was collected in a pitfall trap in the montain forest. The label does not mention the altitude, but in conformity with the Google Earth satellite imagery data its possible range should be limited to values from 1500 m (the summit of Mt Kasigau) to 600 m (the altitude of the surrounding cultivated plains).