Carrhotus atratus sp. nov.

urn:lsid:zoobank.org:act: D26852D1-B21E-41CE-8291-78FBAD0DE9A7

Figs 5A–I, 6A–G, 7A–D, 17

Diagnosis

Males of C. atratus sp. nov. can be separated from those of other congeners by their triangular-shaped PLP and cone-shaped anticlockwise directed embolus tip (Figs 6E–F, 7A–B). The palp of C. atratus closely resembles that of C. erus Jastrzebski 1999; however, its PLP is relatively short, rounded and RTA is not pointed. RTA is smaller and tapered (Fig. 6F) than in other Carrhotus species from Sri Lanka. Females are distinguished by the prominent hood at the CO and hook-shaped CD (Fig. 7C–D).

Etymology

The specific epithet is derived from the Latin word ‘ atratus ’ meaning ‘darkened’, loosely referring to its blackish body colour.

Material examined

Holotype SRI LANKA • ♂; Northern Province, Jaffna District, Mandaitivu; 09°61′67″ N, 79°99′22″ E; 12 m a.s.l.; 12 Jan. 2020; S.P. Benjamin et al. leg.; beating; NIFS_SAL_1280.

Paratype SRI LANKA • 1 ♀; same collection data as for holotype; NIFS_SAL_1281 .

Other material

SRI LANKA • 2 ♂♂, 5 ♀♀; same collection data as for holotype but 20–22 Oct. 2016; NIFS_SAL_932 to SAL_938 • 1 ♂, 2 ♀♀; same collection data as for holotype; NIFS_SAL_1282 to SAL_1284 • 1 ♀; Jaffna District, Vantharavathai; 09°37′14″ N, 79°59′52″ E; 9.5 m a.s.l.; 26 Jan. 2021; S.P. Benjamin leg.; beating; NIFS_SAL_1441 .

Description

Male

MEASUREMENTS. TL 4.5, PL 1.92, PW at PLEs 1.5, AL 1.83, AW 1.32. Eye field: diameter of AME 0.4; ALE 0.26; PME 0.06; PLE 0.12; PME–PME 1.34; PLE–PLE 1.3; ALE–PME 0.22; ALE–PLE 0.54. Leg I: Tr 1.02, Fm 0.46, Pt 1, Tb 0.64, Mt 0.5; Leg II: Tr 0.9, Fm 0.46, Pt 0.7, Tb 0.6, Mt 0.52; Leg III: Tr 1.08, Fm 0.46, Pt 0.88, Tb 0.82, Mt 0.44; Leg IV: Tr 0.9, Fm 0.84, Pt 0.4, Tb 0.72, Mt 0.42.

COLOR AND BODY (live spiders). Carapace black, sparsely covered with black hairs; lateral margins sparsely covered with white hairs; posterior region black (Fig. 5A–B, E–F, I). Clypeal region blackish; eyes surrounded by blackish orbital setae. Chelicerae black, curved outer margins, excavated inner margins; two promarginal and one retromarginal teeth. Sternum oval, blackish; labium and maxillae blackish brown, paler outer margins. Abdomen ovoid, sparsely covered with black hairs; anterior margin sparsely covered by white hairs; no prominent pattern present on posterior region, beige pairs of transverse lines covered with white hairs on mid dorsum. Venter blackish with a very broad dark black median region covered with two thin greyish longitudinal lines. Spinnerets blackish, covered with a patch of black hairs dorsally (Fig. 6A–B). Leg I robust; femora I-IV black dorsally; patellae and tibiae black; tarsi and metatarsi of all legs blackish.

PALP. Dark black colour and embolus long, bow-shaped and tip directed anticlockwise, its base visibly separated from tegulum (Figs 6E–F, 7A–B).

Female

MEASUREMENTS. TL 5.75, PL 2.04, PW at PLEs 1.74, AL 2.7, AW 2.22. Eye field: diameter of AME 0.6; ALE 0.2; PME 0.1; PLE 0.2; PME–PME 1.4; PLE–PLE 1.54; ALE–PME 0.32; ALE–PLE 0.72. Leg I: Tr 0.8, Fm 0.46, Pt 0.7, Tb 0.56, Mt 0.44; Leg II: Tr 1.06, Fm 0.34, Pt 0.46, Tb 0.62, Mt 0.52; Leg III: Tr 0.72, Fm 0.46, Pt 0.9, Tb 0.46, Mt 0.54; Leg IV: Tr 0.7, Fm 0.4, Pt 0.8, Tb 0.4, Mt 0.5.

COLOR AND BODY (live spiders). Same as in male except for the following. Clypeal region covered with iridescent hairs providing a metallic sheen; lateral margins of carapace lined by a thin line of white hairs; posterior region black (Fig. 5C–D, G–H). ALEs and PLEs surrounded by blackish orbital setae. Sternum oval, brownish; labium and maxillae reddish-brown, with paler outer margins. Abdomen ovoid, densely covered with rusty brown hairs; anterior margin covered with a thin line of white hairs; pattern present on black background with pair of two white spots anteriorly and pairs of transverse stripes following posteriorly. Mid-dorsum covered with scales of metallic sheen; venter yellowish, with a broad dark brown median region (Fig. 6C–D).

EPIGYNUM. Epigyne with a pair of copulatory ducts with a loop or flap-like structure arising from elongated pear-shaped spermathecae, whose latter part is narrowing. Accessory glands open at 3 o’clock position at narrowing anterior region of lateral walls of spermathecae (Figs 6G, 7C–D).

Distribution and habitat

This species occurs in the mangrove forest, in the arid zone and lowland secondary rainforest of Sri Lanka (Fig. 17). Specimens were collected by beating foliage up to a height of 2 m.