Stenaelurillus sarojinae Caleb & Mathai, 2014

Marathe, Kiran, Sanap, Rajesh, Joglekar, Anuradha, Caleb, John T. D. & Maddison, Wayne P., 2022, Three new and notes on two other jumping spider species of the genus Stenaelurillus Simon, 1886 (Salticidae: Aelurillina) from the Deccan Plateau, India, Zootaxa 5125 (1), pp. 1-19 : 6-8

Stenaelurillus sarojinae Caleb & Mathai, 2014

Figs. 28–51 , 115 .

Stenaelurillus sarojinae Caleb & Mathai, 2014: 64 , f. 24–30. Holotype in Zoological Survey of India, Chennai, India; not examined.

Stenaelurillus sarojinae Caleb, Mungkung & Mathai, 2015: 12 , f. 57–61, 63–81. Male in NCBS; not examined.

Material examined. 11 ♂♂ & 3 ♀♀. INDIA: Karnataka: Mysuru: south of Mysuru , grassland, 12.215 to 12.216 °N 76.625 °E, elev. 763 m asl, 4 July 2019, coll. K. Marathe, W. Maddison, S. Javagal, & Abhijith APC, WPM#19-104 and WPM#19-106 .

Geographic variation. The Mysuru population differs in several respects from that at the type locality in Kadapa, about 400 km NE of Mysuru ( Caleb & Mathai 2014; Caleb et al. 2015). Mysuru males have the dorsum of the abdomen a matte grey, made from a mix of bluish-grey and brown scales, with the balance shifting to dark brown in the posterior quarter. The four major muscle attachment points appear as dark spots. In contrast, Kadapa males have the posterior two-thirds of the abdomen covered uniformly with glossy dark metallic blue scales. Despite this striking difference in markings, the palpal structure is similar enough between these two populations that we are considering them geographic variants. Females of the Mysuru population are rusty coloured, especially the carapace and anterior end of the abdomen, and the white spots on the abdomen are rounder; in contrast, the Kadapa population appear to be brown coloured, and the white areas on the abdomen broader extending horizontally.

Diagnosis. Among the Indian Stenaelurillus with fringed-abdomen, S. sarojinae males uniquely have an embolic process, a bluish-grey or glossy metallic dark blue abdomen, and lateral abdominal fringes that are restricted to the posterior half. S. sarojinae females are similar to others in the groups in having a general drab appearance but pronounced longitudinal bands on the carapace, and a central chevron on the abdomen flanked with white spots medially separates females of this species from others.

Description. Male (based on specimen IBC-BP312/ DDKM21.009). Measurements: Carapace 1.63 long, 1.16 wide. Abdomen length 1.65, width 1.2. Leg lengths: I—3.2 (1.1, 0.5, 0.8, 0.5, 0.3); II—3.4 (1.2, 0.6, 0.8, 0.6, 0.3); III—5.6 (1.8, 0.4, 1.6, 1.3, 0.5); IV—4.5 (1.3, 0.5, 1.1, 1.0, 0.6). Leg formula: III-IV-II-I. Carapace narrow, about as wide as abdomen. Anteriorly black, covered with black scales and hairs, and rust coloured medially. Two yellowishwhite longitudinal stripes running down behind PLEs. Two yellowish-white bands on lateral margins. Clypeus yellowish, sparsely covered with white hairs. Chelicerae vertical, narrow, yellowish-brown, sparsely covered with white hairs. Palp ( Figs. 28, 29, 32, 33 ): Cymbium yellowish with some black. Embolus accompanied with apophysis (appears as a 2-prong fork). Tegular process round. Femur with a distally located ventral process. Legs robust, yellowish orange, except tarsus and metatarsus I black, and tibia I black below and dusky above. Legs covered with cream to orange scales, except first leg, with black setae under patella and more distally. Abdomen with black spot anteriorly with somewhat long black setae, rest covered with greyish-blue setae dorsally; four somewhat black spots medially located. Posterior edge fringed with black and yellowish setae. Spinnerets black.

Female (based on specimen IBC-BP313/ AS 19.6591). Measurements: Carapace 1.38 long, 1.04 wide.Abdomen length 1.97, width 0.97. Leg lengths: I—3.2 (1.2, 0.6, 0.6, 0.4, 0.3); II—3.4 (1.3, 0.6, 0.6, 0.6, 0.4); III—6.2 (1.9, 0.9, 1.4, 1.3, 0.6); IV—5.2 (1.4, 0.6, 1.3, 1.3, 0.7). Leg formula: III-IV-II-I. Carapace slightly narrower than abdomen.Anteriorly dark brown, covered with black scales and hairs, white scales along PMEs and PLEs, remaining dominantly reddish-brown covered with black scales. Two white longitudinal stripes running down behind PLEs. Two white bands on lateral margins. Clypeus reddish brown, sparsely covered with white setae. Chelicerae as in males. Legs robust, yellowish orange, sparsely covered with black, orange, and white scales. Abdomen dominantly brownish black with medial longitudinal yellowish-brown chevron flanked by two white spots medially. Yellowishwhite band on sides encompasses central brownish-black area. Spinnerets brownish black with white tips. Epigyne ( Figs. 30, 31, 34, 35 ): What we interpret as the ECP is small and circular, hidden in a sclerotized fold projecting over the epigastric furrow. Copulatory openings inverted U shaped, located anterior to ECP.

Natural history. Stenaelurillus sarojinae was locally common in open grassland, rarely in shaded areas, often actively moving amid grass tufts, on the dirt and on rocks. We (KM & Abhijith APC) noticed a male on a pebble lifting and shaking its fringed blue abdomen in a pose reminiscent of the mating displays of Maratus species ( Girard et al. 2011) and Habronattus species (e.g., Elias et al. 2012), raising the possibility that these and other Stenaelurillus may have complex courtship worthy of further investigation. The male was displaying, surprisingly, simultaneously to at least 5 females standing side by side, all of which were collected subsequently and found to be immature.

Figures

FIGURES 115. The type localities (solid black) and distribution records (solid white) of Stenaelurillus species studied in this work.

FIGURES 28–39. Stenaelurillus sarojinae, Mysuru population. 28, 32 male left palp, ventral view (IBC-BP312/ DDKM21.009); 29, 33 same, retrolateral view; 30, 34 epigyne, ventral view (IBC-BP313/ AS19.6591); 31, 35 vulva, dorsal view; 36 male, dorsal view; 37 same, ventral view; 38 female, dorsal view; 39 same, ventral view. Scale bars: 0.1 mm for genitalia and 1.0 mm for bodies.

FIGURES 40–51. Stenaelurillus sarojinae, Mysuru population, habitus photographs. 40–42 male (AS19.6479); 43 male (AS19.6532); 44–46 male (AS19.6532); 47–48 male (AS19.6544); 49–51 female (AS19.6583). Scale bars: 1.0 mm.