Stenaelurillus lesserti Reimoser, 1934

Sebastian, Pothalil A., Sankaran, Pradeep M., Malamel, Jobi J. & Joseph, Mathew M., 2015, Description of new species of Stenaelurillus Simon, 1886 from the Western Ghats of India with the redescription of Stenaelurilluslesserti Reimoser, 1934 and notes on mating plug in the genus (Arachnida, Araneae, Salticidae), ZooKeys 491, pp. 63-78 : 67-73

Taxon classification Animalia Araneae Salticidae

Stenaelurillus lesserti Reimoser, 1934 Figs 4 A–C, 5 A–G, 6 A–C, 7B, 10 A–J, 11 A–F

Stenaelurillus lesserti Reimoser, 1934: 504, figs 25-26 (Description and illustration of ♂ and ♀); Prószyński 1984: 139 (Illustration of ♀); Wesolowska 2014: 248, figs 1 A–B, 2 A–F, 3 A–D (Re-examined the original type series of Stenaelurillus lesserti ; description and illustration of ♂ and ♀).

Material examined.

(ADSH 83503Ai)-4 males, 5 females: India, Kerala, Ernakulam, Cherukadu (10°08'22.48"N, 76°40'02.14"E) in Bhoothathankettu Forest Reserve (10°08'22.79"N, 76°40'02.09"E), 37 m. alt., Pradeep M. S., 10. X. 2013, by hand.

Diagnosis.

Males of Stenaelurillus lesserti Reimoser, 1934 can be separated from all other described congeners by a transverse fringe of very thin, hard projections resembling hairs at the anterior edge of the harder shield covering the bulbus (Figs 5 D–G, 10 H–J); females by the presence of unusually enlarged and kidney-shaped spermathecae and the relative position of the copulatory openings (Figs 6 A–B, 11 E–F).

Redescription.

MALE (Figs 4A, 4C, 10 A–G): Prosoma black, thoracic part with broad yellowish-white lateral bands; thoracic region dorsally with paired white longitudinal bands extending back from the rear eyes. Eye field black with covering of violet scales; anterior row of eyes encircled with red and yellow scales and black hairs. Clypeus covered with transverse layers of orange-red, black and green scales and two layers of greyish-black and red hairs. Chelicerae short, yellowish-brown; dorso-laterally covered with thick layer of red, yellow and green hairs; promargin with two, one large and one small, and retromargin with one large teeth (Fig. 4C). Fangs short, yellow. Maxillae and labium black. Opisthosoma U–shaped; dorsum black with an anterior broad transverse white band and posterior three white spots, which together forming an inverted triangle; lateral opisthosoma pale yellow with several broken longitudinal black striations, while venter pale yellow without any striations or spots. Sternum and coxae pale yellow; coxa I retrolaterally black; femur I pro and retrolaterally black with a prolateral red stripe at the middle (Fig. 10G); femur I prolaterally and dorsally provided with a fringe of black hairs, the dorsal one prominent; ventrally with a row of short white hairs; all other leg segments pale yellow with black patches and narrow transverse black stripes. Body length 3.80. Prosoma length 2.08, width (at the middle) 1.47, height (at the middle) 1.27. Opisthosoma length 1.72, width (at the middle) 1.15, height (at the middle) 0.99. Eye diameter: AME 0.34. ALE 0.19. PME 0.04. PLE 0.18. Eye interdistance: AME–AME 0.04. PME–PME 1.15. PLE–PLE 1.07. AME–ALE 0.07. ALE–PLE 0.45. ALE–PME 0.28. PME–PLE 0.17. Clypeus height at AMEs 0.22, at ALEs 0.42. Chelicera length 0.31. Measurements of palp and legs. Palp 1.44 [0.53, 0.19, 0.16, 0.56], I 3.2 [1.07, 0.52, 0.69, 0.44, 0.48], II 2.91 [0.99, 0.45, 0.59, 0.43, 0.45], III 4.68 [1.45, 0.70, 0.94, 1.03, 0.56] IV 4.48 [1.25, 0.75, 0.76, 1.22, 0.50]. Leg formula: 3412. Spination. Palp. 0000 0000 0000 0000; legs: femur I 0700, II 0710, III 0700, IV 0600, patellae I–II 1000, III–IV 1010; tibia I 3004, II 3014, III 3143, IV 4143; metatarsus I 2014, II 2024, III 4043, IV 5062; tarsi I–IV 0000. Copulatory organ (Figs 5 A–G, 10 H–J): Femur black, provided prolaterally and dorsally with a bunch of black hairs (Figs 5 A–C, 10 H–J), the dorsal one is prominent. Patella and tibia pale yellow with ventral black patch. Cymbium and bulb pale yellow; the anterior edge of the harder shield covering the bulbus is provided with a transverse fringe of very thin, hard projections resembling hairs, which are distinctly longer at the retrolateral angle (Figs 5 D–F); embolus short with blunt end, retrolaterally directed with prolaterally directed tip (Figs 5E, 5G); conductor apparently absent; terminal apophysis short, directed at ten o'clock position (Figs 5E, 5G). Tibia with two ventral apophyses (Fig. 5E); VTA 1 is the smallest; VTA 2 with a flattened end (Fig. 5E); both VTA 1 & 2 directed at one o'clock position (Fig. 5E); RTA simple with broad base, pointed end, directed at eleven o'clock position (Fig. 5F).

FEMALE (Figs 4B, 11 A–D): Prosoma black, thoracic part with broad yellowish-white lateral bands; thoracic region dorsally with paired white longitudinal bands extending back from the rear eyes. Eye field black; anterior row of eyes encircled by pale yellow hairs. Clypeus black. Chelicerae short and black; promargin with two, one large and one small, and retromargin with one large teeth. Fangs short, black. Maxillae and labium black. Opisthosoma widely oval; dorsum black with an anterior broad transverse white band and posterior three white spots, which together forming an inverted triangle; lateral opisthosoma pale yellow with several broken longitudinal black striations while venter pale yellow without any striations or spots. Sternum and coxae pale yellow; coxa I retrolaterally black; all other leg segments pale yellow with black patches and narrow transverse black stripes. Palp: posterior 1/4th of femur black; rest of femur and other segments pale yellow. Body length 6.46. Prosoma length 2.97, width (at the middle) 1.86, height (at the middle) 1.49. Opisthosoma length 3.49, width (at the middle) 2.69, height (at the middle) 1.90. Eyes diameter: AME 0.41. ALE 0.22. PME 0.04. PLE 0.15. Eye interdistance: AME–AME 0.02. PME–PME 1.31. PLE–PLE 1.14. AME–ALE 0.05. ALE–PLE 0.38. ALE–PME 0.21. PME–PLE 0.16. Clypeus height at AMEs 0.27, at ALEs 0.44. Chelicera length 0.56. Measurements of palp and legs. Palp 1.5 [0.52, 0.25, 0.24, 0.49], I 3.28 [1.14, 0.58, 0.61, 0.44, 0.51], II 3.16 [1.12, 0.54, 0.58, 0.49, 0.43], III 5.49 [1.75, 0.84, 1.09, 1.14, 0.67], IV 5.13 [1.53, 0.66, 1.07, 1.26, 0.61]. Leg formula: 3412. Spination. Palp. 0100 0000 0000 2231; legs: femur I 0600, II 0700, III 2600, IV 0600; patellae I–II 1000, III–IV 1010; tibia I 1005, II 2004, III 4043, IV 4343; metatarsi I–II 2014, III 3324, IV 3323; tarsi I–IV 0000. Copulatory organ (Figs 6 A–C, 11 E–F): Copulatory opening is nearly diamond shaped (Fig. 6A) and placed near the posterior margin of the epigyne (Figs 6A, 11E). Spermathecae are much enlarged and kidney shaped (Figs 6B, 11F).

Variation.

Male: (n = 4) Body length 3.24-3.80. Female: (n = 5) Body length 6.15-6.46.

Habitat.

Rocky area having patches of grass and herbaceous vegetation in a semi-evergreen forest (Fig. 12B).

Distribution.

India, Sri Lanka ( Wesolowska 2014).

Distribution in India.

Kerala (new record) and Tamilnadu ( Reimoser 1934).

Note.

Mating plugs, which are supposed to function as paternity protection devices ( Uhl et al. 2010; Herberstein et al. 2012), are not very unusual in the animal kingdom and their presence have been described in a number of spider families including Salticidae . Mating plugs are reported in a total of 10 genera and 17 species of salticid spiders ( Uhl et al. 2010). Mating plug was observed in the copulatory opening of the two Stenaelurillus species described in this paper. The left copulatory opening of both Stenaelurillus albus sp. n. and Stenaelurillus lesserti were found to be sealed with amorphous secretions (whether male or female origin is unclear) (Figs 7 A–B, arrows). Compared to Stenaelurillus lesserti , the mating plug of Stenaelurillus albus sp. n. is more prominent and covering nearly the whole area of the left copulatory opening and the surrounding epigynal region.