Nemesia africana (C.L. Koch, 1838 )

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 : 71-77

Nemesia africana (C.L. Koch, 1838)

( Figs 1–16)

Cteniza africana C.L. Koch, 1838: 10 , fig. 344 (♀); 1841: 211; Wagner 1841: tbl. X (♀).

Mygale africana : Walckenaer 1841: 431.

Mygalodonta africana : Simon 1864: 75.

Nemesia africana : Simon 1892: 112; Strand 1907: 12 (♀); Reimoser 1919: 6; Frade & Bacelar 1931 b: 237; Bacelar 1932: 21; Denis 1937: 1029 (♀); Roewer 1942: 179; Bonnet 1958: 3036.

Diagnosis: Nemesia africana somewhat resembles N. caementaria , N. algerina n. sp., and N. tanit n. sp. in its habitus and general colouration (particularly in the presence of the scalloped chevrons), but differs from them as well as from other Nemesia spp. by an unusually fine dorsal abdominal pattern ( Figs 1, 11 cf. Figs 17, 26, 135). Unlike its congeners featuring the metatarsal preening combs, N. africana has these combs on both pairs of posterior metatarsi – III and IV (not exclusively on metatarsus IV). While the bilaterally toothed embolus characteristic for males of N. africana shows some similarity to the dentate emboli in males of N. meridionalis (Costa, 1835) and several undescribed Nemesia spp. , it nonetheless differs in its shape from those structures ( Fig. 8 cf. Decae 2012: fig. 1Bf; Isaia & Decae 2012: figs 3, 4). The configuration of the spermathecae in N. africana only slightly resembles that in N. tanit n. sp. ( Figs 14, 15 cf. Fig. 139) and differs to a greater extent from those in other Nemesia spp.

Redescription: Male (MNHN 12671/AR4428; Fig. 1): Body length 13.30.

Colour in alcohol: cephalothorax, palps and legs dorsally medium brownish orange, ventrally light yellowish brown, with darker reddish brown chelicerae and asterisk median figure on carapace; eye tubercle intensely dark brown; abdomen dorsally medium yellowish brown with grayish tint, ventral part of abdomen and PMS pale yellowish brown; dark brown dorsal abdominal pattern: narrow and slightly twisted median stripe fused with several paired dentate (festoon-edged) chevrons.

Cephalothorax dorsally and ventrally as in Figs 2 and 4, respectively. Carapace 5.04 long, 4.02 wide. Eye tubercle as in Fig. 3. Eye diameters and interdistances: AME 0.16(0.22), ALE 0.24, PLE 0.20, PME 0.15, AME–AME 0.14(0.08), ALE– AME 0.12(0.09), ALE–PLE 0.08, PLE–PME 0.04, PME–PME 0.41. Chelicerae: each furrow with 6 promarginal teeth and about 15 tiny mesobasal denticles; rastellum with 3 heavy cone teeth and about 15 smaller spines in front of cheliceral fang. Labium 0.45 long, 0.93 wide. Sternum 2.69 long, 2.06 wide. Maxillae without cuspules.

Palp and leg structures. Tibia and metatarsus I as in Fig. 5. Spines (tarsi I–IV aspinose). Palp: femur d1–1–1–2, pd1; patella p1; tibia with 6–7 apical and subapical dorsal spines arranged in two rows; cymbium with ca. 15 short dorsal spines. Leg I: femur d1–1–1–1–3, pd1, rd1; patella p1; tibia p0–1–1, r0–1–1, pv0–1–M; rv1–1–1; metatarsus p0–1–1, r0–1–1, v0–1–2. Leg II: femur d1–1–1–1–2, pd1, rd1–1(0)–1; patella p1–1, tibia p1, r1–1, v2–2–3; metatarsus p1, r1–1, v2–2–3. Leg III: femur d 1–1–1–1–2(3), pd1–1–1, rd1–1–1; patella d1–1, p1–1, r1; tibia d2–1–1, p1–1–1, r1–1, v2–2–3(2); metatarsus p1–1–2–1, r1–1–1, v2–2–3. Leg IV: femur d1–1–1– 1–3(2), pd1–1–1, rd1–1–1–1; patella p1–1, r1; tibia d2–1–1–0, p1–1–2(1), r1–1, v2–2–3; metatarsus d1–1–1–1–1, p1–1–1, r1–1–1, v2–2–3. Metatarsal preening combs present on retroventral apical edge of metatarsus III (ensmalled) and IV (normally developed). Scopula entire and distal on metatarsusi I and II, entire and mixed with longer setae on tarsi I and II; elsewhere absent. Trichobothria: 2 rows of 9–10 in each row on tibiae, 8–9 on metatarsi, 10–13 on tarsi, 7–8 on cymbium. Paired claws on tarsi I–III, and IV with 9–10, and 7–9 teeth in each row, respectively. Unpaired tarsal claw sharply curved.

Leg and palp measurements:

Palp

I II III IV

Femur 2.50 4.15 3.80 3.28 4.18

Patella 1.26 2.34 2.15 1.80 2.34

Tibia 1.64 2.77 2.57 2.15 3.82

Metatarsus – 2.81 2.89 3.09 4.29

Tarsus 0.91 2.43 2.20 2.23 2.53

Total 6.31 14.50 13.61 12.55 17.16

Copulatory organs. Palpal tibia as in Figs 6, 7. Embolus moderately long, tapering, curved and bilaterally dentate, with 2–3 pro- and retrolateral micro-teeth ( Figs 7, 8).

Spinnerets as in Fig. 9. PMS: length 0.27; diameter 0.10. PLS: maximum diameter 0.46; length of basal, medial and apical segments 0.88, 0.55, 0.15, respectively; total length 1.58; apical segment domed.

Female (MNHN 1176/AR4304; Fig. 10): Body length 20.90.

Colour in alcohol: in general as in male, but stellate pattern of carapace and chelicerae noticeably darker (dark reddish brown vs. medium reddish brown in male).

Cephalothorax dorsally and ventrally as in Figs 11 and 13, respectively. Carapace 6.82 long, 5.82 wide. Eye tubercle as in Fig. 12. Eye diameters and interdistances: AME 0.19(0.27), ALE 0.37, PLE 0.27, PME 0.17, AME–AME 0.26(0.18), ALE– AME 0.18(0.14), ALE–PLE 0.13, PLE–PME 0.07, PME–PME 0.65. Chelicerae:

each furrow with 6 promarginal teeth and 4 small plus about 15 tiny mesobasal denticles; rastellum with 5–6 long heavY teeth plus 20–25 smaller subequal spines in front of cheliceral fang and on mound. Labium 0.77 long, 1.48 wide. Sternum 3.80 long, 2.99 wide. Each maxilla with 6 cuspules confined to inner maxillary heel.

Palp and leg structures. Spines: all femora with 6 (d1–1–1–1–2) very thin bristle-like spines; femora III–IV with clusters of dense and short dorsoapical setae; palpal tarsus and tarsi I–II each with 5–8 reduced ventroapical spines; palpal patella, patellae I, IV and tarsi III–IV aspinose. Palp: femur pd1; tibia v2–2–4(3); tarsus v2. Leg I: femur pd1, tibia v1–1–3(2); metatarsus v2–2–2. Leg II: femur pd1; patella p1; tibia v1–1–3(2); metatarsus v2–2–2. Leg III: femur rd1–1; patella p1–1; tibia p1–1, r1–1, v1–1–3; metatarsus p1–1–1, r1–1–1, v2–2–3. Leg IV: femur rd1(0); tibia r1–1, v2–2–3; metatarsus p1–1–1, r1–1–1, v2–2–3(2). Metatarsal preening combs as in male, present on metatarsi III and IV. Scopula entire and distal on metatarsi I and II; very narrowly divided on palpal tarsus and tarsus I; more widely divided on tarsus II; elsewhere absent. Trichobothria: 2 rows of 8–11 in each row on tibiae, 13–16 on metatarsi, 15–17 on tarsi, 13 on palpal tarsus. Palpal claw with 4 teeth on promargin. Paired claws on tarsi I and II with 2–3 teeth in inner and 3–4 teeth in outer rows, paired claws on tarsi III and IV with 0–2 and 3–4 teeth in these rows, respectively. Unpaired tarsal claw sharply curved.

Leg and palp measurements:

Palp I II III IV Femur 3.64 4.46 3.91 3.67 5.10 Patella 2.03 2.81 2.68 2.32 3.46 Tibia 2.01 2.75 2.48 2.25 4.67 Metatarsus – 2.04 2.00 2.58 4.24 Tarsus 1.99 1.45 1.44 1.71 2.17 Total 8.67 13.51 12.51 12.53 19.64

Copulatory organs. Spermathecae moderately long and club-shaped ( Figs 14 and 15).

Spinnerets as in Fig. 16. PMS: length 0.21; diameter 0.10. PLS: maximum diameter 0.81; length of basal, medial and apical segments 0.94, 0.32, 0.19, respectively; total length 1.45; apical segment domed.

Variation: Carapace length in males 4.4–5.3 mm, in females 5.2–8.6 mm. Number of maxillary cuspules varies from 2 to 6. Darker dorsal pattern of the abdomen is less distinct in paler specimens.

Material examined: Algeria: Algiers Province: 1♂, vicinitY of Algiers citY, unknown date and collector (MNHN 6733/AR4458); 4♂ 1♀, same collecting data but xi–xii.1886 (MNHN 9963/AR4475); 3♀, same collecting data but 1891, E. Simon (MNHN 14967/AR4450) ; Blida Province: 3♂ 16♀, surroundings of Blida citY 45 km SW Algiers , unknown collector and date (MNHN 1176/AR4304); 1♂ 2♀, Chiffa, iv.1891, unknown collector (MNHN 12671/AR4428) ; Boumerdès Province: 3♂ 1♀ 1♀ subad., Qued Isser Valley 50 km E Algiers, xi–xii.1886, no other data (MNHN 9966/AR4423) ; Oran Province: 1♀, surroundings of Oran (35°42′N 0°38′W), no other data (MNHN 6163/AR4486) ; Constantine Province?: 1♀, Souk el Harras? (labelled as ” Souk Harras ”, maY also correspond to Souk Ahras), coll. Ler, no other data (MNHN 385/AR4477) .

Distribution: Currently, the species is known only from Algeria, where it occurs in coastal and subcoastal zones in the northern part of the country.

Notes: The second record of this species in the country provided by Lucas (1846) was found during the current study to be based on misidentification and actually related to the occurrence of N. dorthesi (for more details see the corresponding paragraph in the Discussion). Hence, this record has now been transferred to the synonym list of the latter species. The putative records of N. africana indicating its distribution outside Algeria are also considered and disputed in the discussion below.