Nemesia algerina, Zonstein, 2019

Zonstein, Sergei L., 2019, New data on the spider genus Nemesia in Algeria (Araneae: Nemesiidae), Israel Journal of Entomology (Oxford, England) 49 (1), pp. 69-130 : 77-82

Nemesia algerina n. sp.

( Figs 17–31)

LSID: urn:lsid:zoobank.org:act:CD0BF24E-64B5-4C70-9A94-FF8811CB2413 .

Etymology: The species name is a Latinized adjective derived from Algeria / Alger / Algiers and refers to both the country of the type locality and the locality itself.

Diagnosis: In N. algerina n. sp. the dorsal abdominal pattern to some extent resembles that in N. africana (however, in the former both the chevrons and the distance between them are considerably wider; Figs 17, 26 cf. Figs 1, 11). The shape of the palpal organ (displaying a relatively short curved embolus) in N. algerina n. sp. resembles that in the South European N. angustata Simon, 1873 , but differs from the latter in some details: in the new species the embolus is noticeably thicker and tapers more towards the apex and the palpal tibia is armed dorsally with two apical and two subapical spines ( Figs 22–24), while in N. angustata the less tapered embolus is considerably thinner and the dorsal armament of the palpal tibia is represented by three apical and one subapical spines (Frade & Bacelar 1937 b: figs 9, 10; while visiting the MNHN in 2012, I examined the holotype of the latter species, and my observations confirm these data). The shape of the short and diverging spermathecae in N. algerina n. sp. is somewhat similar to that observed in N. asterix Decae & Huber, 2017 , N. bristowei Decae, 2005 , N. ibiza Decae, 2005 , and N. randa Decae, 2005 ( Fig. 30 cf. Decae 2005: figs 32, 39, 67; Decae & Huber 2017: fig. 4F). However, unlike the latter group of species, representatives of N. algerina n. sp. possess medium-sized (not reduced) PMS and lack the preening combs on metatarsus IV.

Description: Male (holotype MNHN 4771/AR4453; Fig. 17): Body length 7.70.

Colour in alcohol: carapace medially and laterally medium ochre brown; clypeus, thoracic fovea, radial grooves, chelicerae and femora I–IV with slightly darker brownish tint; eye tubercle brownish black; palps and most part of legs I–IV light ochre brown; ventral side of cephalothorax, most part of abdomen and spinnerets brownish yellow; darker dorsal abdominal pattern consisting of interrupted median stripe and several paired lateral chevrons medium brown.

Cephalothorax dorsally and ventrally as in Figs 18 and 20, respectively. Carapace 3.54 long, 2.59 wide. Eye tubercle as in Fig. 19. Eye diameters and interdistances: AME 0.12(0.16), ALE 0.18, PLE 0.14, PME 0.10, AME–AME 0.09(0.05), ALE– AME 0.07(0.05), ALE–PLE 0.05, PLE–PME 0.02, PME–PME 0.28. Chelicerae: each furrow with 5–6 promarginal teeth and with about 15 extremely small and poorly discernible mesobasal denticles; rastellum with 4–5 heavy cone teeth in front of cheliceral fang, and with ca. 12 smaller teeth in front of cone teeth row. Labium 0.26 long, 0.53 wide. Sternum 1.98 long, 1.40 wide. Each maxilla with 3 cuspules confined to inner maxillary heel.

Palp and leg structures. Tibia and metatarsus I as in Fig. 21. Spines (tarsi I–IV aspinose). Palp: femur d1–1–2, dp1; patella p1; tibia with 4 (2 apical and 2 subapical) dorsal spines; cymbium with 12(15) short dorsal spines. Leg I: femur d1–1–1–1–2, pd1–1–1, rd1–1–1; patella p1; tibia p1–1–0, pv1–1–M; rv1–1–1; metatarsus d2, p1–0–1, r0–1–1, v1–1–2. Leg II: femur d1–1–1–1–2, pd1–1–1, rd1–1–1; patella p1–1; tibia p1–1–0, v2–2–2; metatarsus d2, p1–0–1, r0–1–1, v2–1–2. Leg III: femur d 1–1–1–1–2, pd1–1–1, rd1–1–1; patella p1–1–1, r1; tibia d1–1–0, p1–1–1, r1–1–1, v2–2–2; metatarsus d1–1–0–0, pd0–1–1–1, p1–1–1, r1–1–1, v3(2)–2–3. Leg IV: femur d 1–1–1–1–2, pd1–1–0, rd1–1–1; patella r1; tibia p1–1–1, r1–1–1, v2–2–2; metatarsus pd1–1–1–1, p1–1–1, r1–1–1, v2–2–3(2). Metatarsal preening combs absent. Scopula entire and distal on metatarsi I and II; entire on tarsi I and II; very sparse and mixed with setae on tarsus III; absent on tarsus IV. Trichobothria: 2 rows of 7–8 in each row on tibiae, 10–13 on metatarsi, 10–12 on tarsi, 7–8 on cymbium. Paired claws on tarsi I–IV with 8–11 teeth in each row. Unpaired tarsal claw small and sharply curved.

Leg and palp measurements:

Palp I II III IV Femur 1.69 2.90 2.59 2.31 3.20 Patella 0.77 1.64 1.51 1.26 1.85 Tibia 1.14 2.05 1.86 1.62 3.43 Metatarsus – 1.97 1.70 2.21 3.14 Tarsus 0.64 1.45 1.28 1.44 1.67 Total 4.24 10.01 8.94 8.84 13.29

Copulatory organs. Palpal tibia moderately swollen with few dorsal spines: 2+ 2 in subapical and apical rows, respectively ( Figs 22, 23). Embolus relatively short, tapered and slightly curved subapically ( Figs 22, 24).

Spinnerets as in Fig. 25. PMS: length 0.20; diameter 0.14. PLS: maximum diameter 0.31; length of basal, medial and apical segments 0.48, 0.36, 0.08, respectively; total length 0.92; apical segment domed.

Female (paratype MNHN 9964/AR4472; Fig. 26): Body length 9.35.

Colour in alcohol: as in male, with darker and more contrast dorsal pattern on carapace and abdomen.

Entire female body in dorsal aspect and cephalothorax dorsally and ventrally as in Figs 26, 27 and 29. Carapace 3.82 long, 3.11 wide. Eye tubercle as in Fig. 28. Eye diameters and interdistances: AME 0.13(0.17), ALE 0.19, PLE 0.15, PME 0.10, AME–AME 0.10(0.06), ALE–AME 0.08(0.06), ALE–PLE 0.07, PLE–PME 0.03, PME–PME 0.33. Chelicerae: each furrow with 6 promarginal teeth and 15–20 extremely small mesobasal denticles; rastellum: 4 large and about 15 smaller spines in front of cheliceral fang base. Labium 0.44 long, 0.81 wide. Sternum 2.12 long, 1.73 wide. Each maxilla with 3 or 4 cuspules confined to inner maxillary heel.

Palp and leg structures. Spines: palpal tarsus and tarsi I and II each with 7–10 short and small ventroapical spines; palpal patella, patella IV and tarsi III–IV aspinose. Palp: femur d1–1–1–2, pd1; tibia p1–1, v1–1–3; tarsus v2. Leg I: femur d1–1–1–1–2, pd1, patella p1; tibia p1, v1–1–2; metatarsus v2–1–3. Leg II: femur d1–1–1–1–2, pd1; patella p1; tibia p1, v1–1–2; metatarsus p1, v2–1–2. Leg III: femur d1–1–1–1, pd1–1–1, rd1–1–1; patella p1–1, r1; tibia p1–1, r1–1, v2–2–2; metatarsus d1(0) –1–1, p1–1–1, r1–1–1, v2–2–3. Leg IV: femur d1–1–1–1, rd1; tibia r1–1–1, v2–2–2; metatarsus p1–1, pd1–1, r1–1, v2–2–3. Metatarsal preening combs absent. Scopula entire on and distal on metatarsi I and II; narrowly divided on palpal tarsus and tarsus I; widely divided on tarsus II; elsewhere absent. Trichobothria: 2 rows of 7–8 in each row on tibiae, 9–12 on metatarsi, 10–13 on tarsi, 8 on palpal tarsus. Palpal claw with 3 teeth on promargin. Paired claws on tarsi I–II, III and IV with 4–5, 3–5, and 3–4 teeth in each row, respectively. Unpaired tarsal claw small and sharply curved.

Leg and palp measurements:

Palp I II III IV

Femur 2.05 2.71 2.37 2.23 2.96

Patella 1.18 1.67 1.31 1.23 1.76

Tibia 1.28 1.76 1.55 1.19 2.98

Metatarsus – 1.36 1.34 1.55 2.41

Tarsus 1.23 0.95 0.91 1.04 1.27

Total 5.74 8.45 7.48 7.24 11.38

Copulatory organs. Spermathecae stump-like, with short and robust stalks and weakly delimited heads, their right and left branches are slightly inclined sideways in different directions from each other ( Fig. 30).

Spinnerets as in Fig. 31. PMS: length 0.25; diameter 0.17. PLS: maximum diameter 0.41; length of basal, medial and apical segments 0.52, 0.37, 0.09, respectively; total length 0.98; apical segment domed.

Variation: Carapace length in males 3.4–3.5 mm, in females 3.8–4.2 mm. Darker dorsal pattern of the abdomen is almost uniform in all specimens.

Holotype: ♂ Algeria: Algiers Province: surroundings of Algiers (36°45′N 03°33′E), no other data (MNHN 4771/AR4453).

Paratypes: Algeria: 1♂, collected together with holotYpe (MNHN 4771/AR4453) ; 3♀ 2♀ subad., Algiers, no other data (MNHN 6733/AR4458) ; 2♀, same collection data as in holotYpe but xi–xii.1886 (MNHN 9964/AR4472) .

Distribution: Known only from surroundings of Algiers.