Ctenus cochinensis Gravely 1931

Ctenus cochinensis Gravely, 1931

Figs 1B, D–E, 5, 6

Ctenus cochinensis Gravely, 1931: 235, figs 1E, 3C (description and illustrations of male and female). Tikader & Malhotra 1981: 112, fig. 5A–D (description and illustrations of male and female).

Type material. Male and 2 female syntypes of Ctenus cochinensis Gravely, 1931 from INDIA: Kerala: Palakkad: Parambikulam (10o23'34.29''N, 76o46'32.24''E), 597 m alt. (male) and Thrissur: Kavalai (10o16'23.89''N, 76o32'13.03''E), 390 m alt. (females); F.H. Gravely leg.; 16–24 September 1914; repository ZSI; voucher numbers 1506/18 (male) and 1550/18 (females), not examined.

Note. The species was identified using the illustrations given by Gravely (1931) and Tikader & Malhotra (1981).

Material examined. INDIA, Kerala: Thrissur, Chimmony Wildlife Sanctuary, 10o25'6.80''N, 76o32'7.25''E, 709 m alt., 8 May 2013, M.S. Pradeep leg., from ground, by hand: 1 subadult male, 2 subadult females, (ADSH20191) and 23 July 2013: 1 female with egg sac (ADSH20192); Ernakulam, Kothamangalam, Salim Ali Bird Sanctuary (Thattekkadu Bird Sanctuary), 10o7'48.3''N, 76o41'43.24''E, 96 m alt., 22 May 2013, M.S. Pradeep leg., from ground, by hand: 1 subadult male, 1 female, (ADSH20193); Malappuram, Akambadam, 11o18'37.42''N, 76o12'31.68''E, 41 m alt., 23 August 2013, M.S. Pradeep leg., from ground, by hand: 2 females with egg sacs (ADSH20194); Kottayam, Areeppara in Edappady, 9o42'35.62''N, 76o42'48.42''E, 27 m alt., 16 August 2016, M.S. Pradeep leg., from ground, by hand: 1 male (ADSH20195) and 25 March 2017: 1 female (ADSH20196).

Diagnosis. Ctenus cochinensis can be separated from other congeners by the following combination of characters: hook-shaped RTA without apical bifurcation, MA short, roughly squarish, embolus with well-defined, transversely oriented apical part, flat, as wide as long epigynal plate, posteriorly placed epigynal teeth, nearly straight lateral folds of copulatory ducts and peanut-like spermathecae (Fig. 5A–F).

Redescription. Male (based on ADSH20195, Fig. 1D). Carapace pale brownish with yellowish-brown median band; thoracic part provided with narrow, longitudinal yellowish-brown medio-lateral bands and patches. Fovea long (1.41), longitudinal, reddish. Eye field black except between PLEs, which is yellowish-brown; ALEs, PLEs and PMEs basally covered with fine, short white hairs (Fig. 1D). Clypeus, chelicerae, fangs, endites, labium, sternum, and spinnerets pale brownish. Dorsum of chelicerae covered with long brownish hairs; promargin with a thick layer of inwardly curved brownish hairs, with three teeth; retromargin with four. Sternum covered with black hairs. Opisthosoma roughly oval, hirsute; dorsum, laterals, and venter greyish-brown; venter with a broad, inverted triangular, creamy patch. Leg segments pale brownish to brownish with black shades and annulations; all tarsi scopulated, tarsal scopula entire; metatarsus I with entire scopula, distal 2/3rd of metatarsus II scopulated, metatarsi III and IV lack scopula. Body length 10.71. Carapace length 6.39, width 5.44. Opisthosoma length 4.32, width 2.91. Eye diameters: ALE 0.19. AME 0.32. PLE 0.39. PME 0.45. Eye interdistances: ALE–ALE 0.25. ALE–PME 0.08. AME–ALE 0.16. AME–AME 0.18. PLE–PLE 1.52. PME–PME 0.22. Clypeus height at AMEs 0.16, at ALEs 0.67. Chelicerae length 2.06. Measurements of pedipalp and legs: pedipalp 8.42 [3.19, 1.20, 1.28, 2.75], I 23.26 [6.21, 2.81, 6.28, 6.23, 1.73], II 20.12 [5.65, 2.61, 5.02, 5.34, 1.50], III 16.70 [4.93, 2.14, 3.62, 4.65, 1.36], IV 23.89 [6.40, 2.40, 5.37, 7.97, 1.75]. Leg formula: 4123. Spination of pedipalp: femur pld 1 do 4 rld 1, patella pl 1, tibia pl 1 plv 1 rld 1 rlv 1, tarsus/cymbium spineless; legs: femur I pl 1 pld 2 do 3 rld 4, II pl 1 pld 3 do 3 rld 4, III pl 5 do 3 rl 4, IV pld 4 do 3, rld 3; patellae I–IV pl 1 rl 1; tibia I pl 1 plv 5 do 3 rld 2 rlv 5, II pl 1 plv 5 do 3 rl 2 rlv 5, III pl 2 plv 3 do 2 rl 2 rlv 3, IV pl 2 plv 4 do 3 rl 2 rlv 3; metatarsus I pld 2 plv 3 rld 3 rlv 3, II pld 3 plv 3 rld 3 rlv 3 vt 1, III pl 1 pld 3 plv 2 rl 1 rld 3 rlv 3, IV pl 3 pld 1 plv 3 rl 2 rld 3 rlv 4; tarsi I–IV spineless. Pedipalp (Fig. 5A– C): palpal segments brownish with black shades. RTA stout, with broad proximal part, short, distal part with acute tip, appears hook-like in retrolateral view (Fig. 5B–C). Ventro-lateral tibial apophysis short, thumb-like, directed at 2-o’clock in ventral view (Fig. 5B). Cymbium tip conical, without basal extension, with short, acute, retrolateral cymbial tooth (Fig. 5B–C). Tegulum highly sclerotised, with a median membranous pit (Fig. 5B). Subtegulum highly sclerotised. MA short, nearly rectangular, baso-retrolateral, with a slight apico-prolateral extension (Fig. 5B). Embolus apically with a prolateral curvature, with blunt tip, narrow in ventral view (Fig. 5A–B). Conductor transparent, apico-retrolateral, rounded in ventral view (Fig. 5A–C).

Female (based on ADSH20196) (Fig. 1B, E). Like male except the following. Carapace brownish with pale brown median band; thoracic part provided with narrow, longitudinal, pale brown medio-lateral bands. Fovea (1.08) dark. Eye field brownish except between PLEs, which is pale brown. Clypeus, chelicerae, fangs, endites, labium, and sternum brownish. Dorsum, laterals and venter of opisthosoma blackish-brown with inconspicuous black spots and W-shaped markings; venter with paired median longitudinal bands formed of pale yellowish spots. Spinnerets pale yellowish with black shades. Leg segments brownish. Body length 12.72. Carapace length 6.49, width 5.11. Opisthosoma length 6.23, width 4.11. Eye diameters: ALE 0.21. AME 0.25. PLE 0.36. PME 0.47. Eye interdistances: ALE–ALE 1.36. ALE–PME 0.09. AME–ALE 0.51. AME–AME 0.15. PLE–PLE 1.58. PME–PME 0.25. Clypeus height at AMEs 0.14, at ALEs 0.58. Chelicerae length 2.85. Measurements of palp and legs: palp 6.79 [2.46, 1.26, 1.43, 1.64], I 16.45 [4.74, 2.69, 4.15, 3.76, 1.11], II 15.20 [4.53, 2.55, 3.54, 3.48, 1.10], III 13.26 [4.05, 1.97, 2.87, 3.44, 0.93], IV 19.18 [5.37, 2.36, 4.30, 5.76, 1.39]. Leg formula: 4123. Spination of palp: femur pld 2 do 2 rld 1, patella pl 1, tibia pl 2 rl 1 rld 2, tarsus pl 2 pld 1 rl 2; legs: femur I pld 2 plv 1 do 3 rld 3, II pl 2 pld 2 do 3 rld 3, III plv 4 do 4 rlv 4, IV pld 4 do 3, rld 1; patellae I–II spineless, III–IV pl 1 rl 1; tibiae I–II plv 5 rlv 5, III pl 2 plv 3 do 2 rld 2 rlv 3, IV pl 2 plv 3 do 3 rl 2 rlv 3; metatarsus I plv 3 rlv 2, II plv 3 rlv 3, III pl 3 pld 1 plv 3 rl 2 rld 2 rlv 3, IV pl 3 pld 1 plv 3 rl 3 rld 2 rlv 4; tarsi I–IV spineless. Epigynum (Fig. 5D–F): epigynal plate flat, nearly as wide as long, with distinct short, wide epigynal field (Fig. 5D, F). Copulatory openings postero-lateral to the epigynal plate, masked by epigynal plate (Fig. 5E, arrows). Epigynal teeth simple, placed postero-laterally to epigynal plate (Fig. 5D–E). Copulatory ducts short, wide (Fig. 5E); lateral folds well marked, slightly diagonally oriented, continuous with epigynal teeth (Fig. 5E). Spermathecae peanut-shaped, obliquely oriented, close to each other, with two differently sized chambers (Fig. 5E, 1 & 2). Fertilization ducts short, narrow, with slightly upturned apical part (Fig. 5E).

Variation. Adult females (n=5): body length 10.43–12.72. The epigynum of the female specimen from the Salim Ali Bird Sanctuary (ADSH20193) has wavy antero-lateral margins and its epigynal teeth are placed close to the posterior epigynal border line (Fig. 5G).

Distribution. India (Kerala) (Fig. 6).