Loxosceles imazighen Ribera & Massa, 2021

Massa, Marc & Ribera, Carles, 2021, The Mediterranean species of genus Loxosceles Heineken & Lowe, 1832 (Araneae Sicariidae): Loxosceles imazighen sp. n. from Morocco and first description of the female of L. mrazig Ribera & Planas, 2009 from Tunisia, Zootaxa 5071 (3), pp. 326-348 : 334-339

Loxosceles imazighen Ribera & Massa sp. n.

Figures 3–5

Type material. Holotype ♂ LX1994, Morocco: Errachidia Province , Kef Aziza Cave, near Boudenib, 1069 m.a.s.l., 32° 01’ 48.14” N, 03° 47’ 06.72” W, 10 February 2012 (Planas, E. & Rodríguez, M. leg) . Paratypes 1 ♀ LX1988 (female description is based in this specimen), same locality and data as holotype . 4 ♀ (LX1980, LX1981, LX1995, LX1999), 4 ♂ (LX1983–LX1986), 8 ♀ sub. (LX1982, LX1987, LX1989, LX1990, LX1992, LX1993, LX1996, LX1997) and 5 juvs. (LX1977–1979, LX1991, LX1998), same locality and data as holotype .

Other material examined. MOROCCO: Errachidia Province : 1 ♀ (LX1974) and 2 ♀ sub. (LX1975, LX1976) near Rissani, 823 m. a.s.l., 31° 17’ 56.04” N, 04° 24’ 01.22” W, 9 February 2012 (Planas, E. & Rodríguez, M. leg) . Figuig Province : 1 ♀ (LX2000) and 2 juvs. (LX2001, LX2002), Jbel Maïz, near Figuig, 1295 m.a.s.l., 32° 14’ 17.23” N, 01° 43’ 06.38” W, 11 February 2012 (Planas, E. & Rodríguez, M. leg) ; 1 ♀ sub. (LX2004) and 2 juvs. (LX2003, LX2005), near Bouanane , 979 m. a.s.l., 32° 05’ 38.15” N, 03° 06’ 49.79” W, 12 February 2012 (Planas, E. & Rodríguez, M. leg) ; Zagora Province : 3 juvs. (LX1971–1973), Jbel Saghro, near Amguene n’Sfia, 1321 m.a.s.l., 31° 01’ 01.16” N, 05° 57’ 02.2” W, 8 February 2012 (Planas, E. & Rodríguez, M. leg) .

Etymology. The name of this species refers to the Berbers peoples of North Africa. Many Berbers are called Imazighen (their singular is Amazigh), which means “free men”, to whom we dedicate this species. The species epithet is a noun in apposition.

Diagnosis. Loxosceles imazighen sp. n. differs from L. mrazig in the shape and proportions of the male palpal tibia ( Figs. 3 B, D–E ) and the shape and disposition of the seminal receptacles in females ( Figs. 4 B–D , 5 A–F ). In L. mrazig the male palpal tibia is short, oval, slightly longer than wide (0.63 long, 0.54 wide), almost circular, while in L. imazighen sp. n. the male palpal tibia is clearly longer than wide, sharply oval. (0.74 long, 0.54 wide). In females, L. imazighen sp. n. differs from L. mrazig by the shape and disposition of the vulva inner lobe ( Figs. 4 B–D , 5 ). In the new species the inner lobe is approximately twice as long as the outer lobe while in L. mrazig the inner lobe is more than two-fold longer. In L. mrazig the basal part of the inner lobe is directed toward the center, then strongly curved and pointing ventrally. In L. imazighen sp. n. the basal part of the inner lobe is abruptly curved pointing apically and continues forming a sharp curve pointing ventrally. Both species can also be distinguished by the leg length/carapace length ratios ( Fig. 8 ). In L. mrazig males and females show proportionally shorter legs than those of L. imazighen sp. n.

Description. Male (Holotype LX1994). Left palp removed and conserved in a vial with specimen. Left legs I to IV detached and conserved in vials with specimen. Coloration: Carapace pale yellow, median groove, clypeus and pars cephalica slightly darkened. Dark V-mark not contacting in the posterior vertex of pars cephalica. Black eye tubercles ( Fig. 3-A ). Sternum pale yellow as the carapace. Chelicerae, labium and gnathocoxae reddish-brown, darkened in its distal part. Legs pale yellow with its apical segments slightly darkened and covered by short and long setae. Palp pale yellow and darkened in its apical segments. Opisthosoma pale yellow. Prosoma: Carapace slightly longer (3.13) than wide (2.79) ( Fig. 3 A ), truncated behind, widely rounded on sides, narrowed in front. Carapace evenly convex with short black setae. Fovea clearly visible. Larger setae or bristles in a single row on the side margin of the carapace pointing anteriorly. Pars cephalica elongated (2.11 long, 0.99 wide) slightly higher than the rest of the prosoma. Long setae forming seven parallel rows on the pars cephalica. Clypeus height 0.35. Eye sizes: ALE: 0.18, PME: 0.12, PLE: 0.19. Distance between ALE and PME 0.18. Sternum longer (1.73) than wide (1.37). Opisthosoma: Elongate oval in dorsal view (4.42 long, 2.62 wide), coated with short setae. Legs: leg formula 2 1 4 3; Leg 1 (27.96): femur 7.60, patella 1.20, tibia 8.72, metatarsus 8.97, tarsus 1.47; Leg 2 (30.32): femur 8.24, patella 1.17, tibia 9.59, metatarsus 9.78, tarsus 1.54; Leg 3 (23.58): femur 6.66, patella 1.13, tibia 6.58, metatarsus 7.92, tarsus 1.29; Leg 4 (26.69): femur 7.28, patella 1.01, tibia 7.52, metatarsus 9.38, tarsus 1.50. Legs covered by short and long thicker setae. Palp: 3.07 long. Femur cylindrical (1.30 long, 0.29 wide). Patella subglobular, slightly longer (0.39) than wide (0.34). Tibia (0.74 long, 0.54 wide) oval in dorsal view, paunchy ventrally, rounded more abruptly toward the patella than the tarsus. Tarsus (0.64 long), rounded apically, shorter than the tibia. Bulb (0.48 wide) globular, shorter than the tarsus. Bulb width more than two-fold wider than embolus base. Embolus long (0.74) and curved, slightly more pronounced at its mid-length, and displaying a sinuous curve in its apex ( Fig. 3 C ). Female (Paratype LX1988) Genitalia removed and conserved in a vial with specimen. Right leg II removed and conserved in a vial with specimen. Right leg IV missing. Coloration: Similar to male except for the carapace, which is slightly darkened, sternum yellowish, labium and gnathocoxae orange yellowish, darkened in its distal part. Legs subtly more yellowish than those of the male. Palps pale yellowish, slightly pale reddish in its apical segments. Prosoma: Carapace slightly longer (3.17) than wide (2.87). Pars cephalica 2.22 long, 1.00 wide ( Fig. 4 A ). Clypeus height 0.4. Eye sizes: ALE: 0.17, PME: 0.13, PLE: 0.17. Distance between ALE and PME 0.19. Sternum longer (1.70) than wide (1.39). Opisthosoma: Elongate oval in dorsal view (4.38 long, 2.50 wide). Legs: leg formula 4 2 1 3; Leg 1 (21.47): femur 6.13, patella 1.18, tibia 6.40, metatarsus 6.35, tarsus 1.41; Leg 2 (22.08): femur 6.34, patella 1.17, tibia 6.54, metatarsus 6.65, tarsus 1.38; Leg 3 (18.88): femur 5.59, patella 1.12, tibia 5.04, metatarsus 5.96, tarsus 1.17; Leg 4 (22.43): femur 6.29, patella 1.18, tibia 6.05, metatarsus 7.53, tarsus 1.38. Palp (3.62): femur 1.21, patella 0.38, tibia 0.81, tars 1.22. Vulva: as in Fig. 4 B–D ). Genital opening connects to two large slightly rounded pouches sclerotized at the edges. Base of seminal receptacle conical and wide. Markedly reinforced laterally with a curved, dark, sclerotized band. Medium part short, slightly conical, curved toward the center and bifurcated in two lobes. The outer lobe is short and tapered or subglobular, pointing to the center, whereas the inner is approximately twice as long. Its basal part is directed toward the apically, strongly curved and pointing ventrally. Seminal receptacles separated at their closest point by more than the apical diameter of the outer lobe. Inner and outer lobe not touching each other by roughly the diameter of the outer lobe.

Variability. Genital morphology shows variability in females ( Fig. 5 A–F ). The inner lobe can be wider as in LX1981, LX1974 ( Fig. 5 A–B ) and less abruptly curved as in LX1981 ( Fig. 5 B–D ). The outer lobe can be shorter and can point ventrally as in LX1981, LX1974 ( Fig. 5 E–F ). The outer lobe can be hidden by the inner lobe in a dorsal view as in LX1981 ( Fig. 5 B ).

Distribution. Known for five localities in the provinces of Errachidia, Figuig and Zagora, located south of the Moroccan Atlas ( Fig. 1B ). This species ranges to the south of the Moroccan Atlas, from Figuig (1295 m.a.s.l.) near the Algerian border, to Amguene n’Sfia (1321 m.a.s.l.). This whole area is open to the warm and dry winds of the Sahara. The average annual precipitation is only 100 mm on the southern slope and 300 mm at the top of the mountain range. The landscape is very arid with plateaus, peaks and plains. The most common environment is the vast spaces of bare rocks. The specimens were collected between 623 and 1321 m.a.s.l. under stones and in caves. In the Anti-Atlas, the most southwestern part of the Atlas mountain range, this species has not been found, possibly due to this area having a high human activity and still preserving green valleys and true oases that are quite well irrigated and cultivated (e.g. Tafraute), which contrast strongly with the steppe and the arid landscape of the easternmost exposed slopes.

Figures

FIGURE 1. Sampling localities of the specimens included in this study. A Western Mediterranean; B Loxosceles imazighen sp. n. from Morocco; C Loxosceles mrazig from Tunisia and Algeria.AL = Algeria, MA = Morocco and TN = Tunisia.

FIGURE 3. Loxosceles imazighen sp. n., male holotype (LX1994 (MA3)). A carapace, dorsal view; B, D, E palp, prolateral, retrolateral and dorsal views; C bulb and embolus apical view. Scale bars in mm.

FIGURE 4. Loxosceles imazighen sp. n., female paratype (LX1988 MA3). A carapace, dorsal view; B–D vulva dorsal, anterior and ventral views. IL = Inner lobe and OL = Outer lobe. Scale bars in mm.

FIGURE 5. Loxosceles imazighen sp. n., female genitalia variability. A, C, E vulva of LX1974 (MA4) dorsal, ventral and anterior views; B, D, F vulva of LX1981 (MA3) dorsal, ventral and anterior views. IL = Inner lobe and OL = Outer lobe. Scale bars in mm.

FIGURE 8. Graphical representation of the leg length/carapace length ratios for Leg 1 to Leg 4 in Loxosceles imazighen sp. n. and Loxosceles mrazig. A. males leg length/carapace length ratios; B. females leg length/carapace length ratios.