Onomastus corbetensis, Benjamin, Suresh P. & Kanesharatnam, Nilani, 2016

Benjamin, Suresh P. & Kanesharatnam, Nilani, 2016, Description of three new species of the tropical Asian jumping spider genus Onomastus Simon, 1900 from high altitude cloud forests of Sri Lanka (Araneae: Salticidae), Zootaxa 4205 (5), pp. 431-453 : 436-439

Onomastus corbetensis sp. nov.

( Figs 4 A–D, 5A–D, 6A–E)

Type material. Holotype: Male (IFS_ SAL 559 ), Sri Lanka, Central Province, Kandy District, Corbett’s Gap , Knuckles range, 1360 m, 0 7°21’40’’N, 80°50’00’’E, hand collection, 12 Aug. 2010, S.P. Benjamin & S. Batuwita . Paratype. Female (IFS_ SAL 560 ), same locality and collection data, 19 Aug. 2010.

Other material examined: 1 male, 2 females (IFS_ SAL 561–563 ), same locality and collection data, 19 Aug. 2010.

Etymology. Named after the type locality; to be treated as an adjective.

Diagnosis. Males are distinguished by the strongly forked MA with a pleated prolateral branch and a tapering, hook-shaped tip ( Figs 5 A, 6B, D). Females are distinguished by the shape of the epigyne, rounded spermathecae with shallow indentation in mid-lateral wall ( Fig 5 C–D). This species is closely related to O. rattotensis by the strongly bifurcated distal end of MA, pleated prolateral arm, well-developed curved retrolateral arm, shape of conductor spur and rounded spermathecae. However, it differs by the presence of a hook-shaped prolateral arm, retrolateral arm terminating in faintly serrated tip in males and broad anterior epigynal border in females.

Description. Male holotype: pale green in life; ethanol preserved specimens light yellow. Chelicerae pale green with 3 promarginal, 7 retromarginal teeth. Pale green labium, as wide as long. Scutiform sternum with vague margins. Ocular region densely covered with glossy white hairs. All eyes black, except for the greenish yellow anterior medians, placed on low, black tubercles ( Figs 4 A–B). Eye field broader anteriorly than posteriorly, occupying nearly half of the prosoma. PMEs much smaller positioned on black tubercles. Median ocular quadrangle wider than long. Prosoma moderately high, rounded, slightly longer than wide. Posterior prosoma slopes gradually, rounded, without any truncation. Abdomen: elongate, ovoid, longer and narrower than prosoma, tapering toward posterior end. Dorsum pale green with dull green blotches on the lateral sides ( Figs 4 A–B). Venter pale green, no markings, spinnerets pale green. Legs: pale green without any markings. Male palp: pale green palp with faint brown palpal tibia, cymbium and bulbus. Cymbium with distal finger-like extension. Highly sclerotized, branched median apophysis. Pleated prolateral branch of MA with hook-shaped tip, retrolateral branch strongly curved, end in a faintly serrated tip ( Figs 5 A, 6B, D). Retrolateral patellar apophysis much broader tapered with rounded tip ( Figs 5 A–B, 6B–C). Filamentous, medium sized embolus originating from alveolar cavity. Conductor tapering ( Figs 5 A–B, 6B–D), lying between median apophysis and tegulum, heavily sclerotized embolic guide, terminus shape of spur with two pointed hooks (as in Figs 5 A, 6B, D, E). Mesal branch of MA supports spur and embolic guide. TA1 long and finger-like, TA3 short, broad. Measurements: TL 2.80, PL 1.50, PW at PLEs 0.95, AL 1.40, AW 0.80. Eye field: Diameter of AME 0.34, PLE 0.12, ALE 0.19, PME 0.02, PME–PME 0.59, PLE–PLE 0.46, ALE–PME 0.12, ALE–PLE 0.31. Leg I: Tr 0.10, Fm 1.30, Pt 0.40, Tb 1.27, Mt 0.84, Ta 0.40; Leg II: Tr 0.12, Fm 1.27, Pt 0.37, Tb 1.24, Mt 0.99, Ta 0.34; Leg III: Tr 0.09, Fm 1.27, Pt 0.34, Tb 1.21, Mt 1.27, Ta 0.31; Leg IV: Tr 0.12, Fm 1.43, Pt 0.34, Tb 1.27, Mt 1.43, Ta 0.31.

Female paratype: As in male, except: yellowish green prosoma, eye field occupying nearly one third of prosoma, prominent black marking in the middle of eye field, broad abdomen with prominent dark green markings ( Figs 4 C–D). Epigyne: very sclerotized. Anterior epigynal border with broad, sclerotized hood-like structure.

Atrial rim present, copulatory openings directly open into spermathecae, spermathecae large, somewhat rounded, small indentation mid-laterally, sclerotized thick walls ( Figs 5 C–D). Fertilization ducts lanceolate, long, slender, originating from middle of postero-dorsal wall of receptacles. Measurements: TL 3.65, PL 1.35, PW at PLEs 0.90, AL 2.20, AW 1.10. Eye field: Diameter of AME 0.37, PLE 0.09, ALE 0.12, PME 0.02, PME–PME 0.62, PLE–PLE 0.67, ALE–PME 0.12, ALE–PLE 0.31. Leg I: Tr 0.16, Fm 1.55, Pt 0.43, Tb 1.21, Mt 0.81, Ta 0.40; Leg II: Tr 0.10, Fm 1.24, Pt 0.31, Tb 1.05, Mt 0.81, Ta 0.31; Leg III: Tr 0.16, Fm 1.30, Pt 0.31, Tb 1.05, Mt 0.81, Ta 0.31; Leg IV: Tr 0.12, Fm 1.33, Pt 0.34, Tb 1.27, Mt 1.33, Ta 0.53.

Figures

FIGURE 4. Onomastus corbetensis sp. nov. from Corbett’s Gap, Knuckles range. A – B. Male in life. C – D. Female in life.

FIGURE 5. Onomastus corbetensis sp. nov. A. Left palp, ventral view. B. Same, retrolateral view. C. Epigyne, ventral view. D. Vulva, dorsal view. Abbreviations: AEB = anterior epigynal border; C = conductor; CY = cymbium; E = embolus; EG = embolic guide; FD = fertilization duct; MAP = mesal branch of MA; PA = patellar apophysis; PMA = prolateral branch of MA; RMA = retrolateral branch of MA; S = spermatheca; SP = spur mesal branch of conductor; T = tegulum; TA 1 = tegular apophysis 1; TA 3 = tegular apophysis 3. Scale bars: D = 0.1 mm, A – C = 0.2 mm.