Carrhotus viduus (C.L. Koch, 1846)

Figs 2C–D, 15A–G, 16A–D, 17

Plexippus viduus C.L. Koch, 1846: 104, fig. 1166.

Carrhotus viduus – Thorell 1891: 142. — Andreeva et al. 1981: 103, figs 39–42. — Prószyński 1984 a: 16; 1992b: 169, fig. 7. — Caleb et al. 2020: 61, figs 57–73, 76–78, 80–82.

Diagnosis

Males of this species are distinguishable by the presence of white longitudinal stripes on the carapace and abdomen, as well as the relatively larger retromarginal cheliceral tooth. The palpal conformation of C. viduus closely resembles that of C. taprobanicus; however, it can be distinguished by the longer, ventrally projecting embolus and its oval base (Fig. 16A). Further, the RTA is less slanted ventrally in C. viduus (Fig. 16A–B). Females can be separated from those of C. taprobanicus by the broader ML and longer CD and FD (Fig. 16C–D). Females can be readily distinguished from those of C. silanthi by the kidney-shaped spermathecae (Figs 12C–D, 16C–D).

Type material

Plexippus viduus C.L. Koch, 1846: 2 ♂♂; depository unknown. Our identification is based solely on the description and illustrations of Prószyński (2009). He mentioned two possible specimens currently deposited in ZMB. However, their geographic origin is ambiguous (see Prószyński 2009).

Remarks

According to Sudhin et al. (2021), C. tholpettyensis Sudhin, Nafin, Caleb & Sudhikumar, 2021 differs by the absence of a pair of white longitudinal stripes found on the abdomen of male C. viduus . The mentioned minor gentilic differences could easily be attributed to intraspecific variation. Thus, we consider C. tholpettyensis as a possible junior synonymy of C. viduus .

Material examined

SRI LANKA – Northern Province • 1 ♂; Jaffna District, Mandaitivu; 09°36′26″ N, 79°59′5″ E; 20–22 Sep. 2016; S.P. Benjamin leg.; beating; NIFS_SAL_958 • 1 ♀; same collection data as for preceding but 26 Jan. 2021; NIFS_SAL_1442 . – Central Province • 1 ♂; Kandy District, Gannoruwa FR; 07°17′16″ N, 80°35′47″ E; 575 m a.s.l; 30 Jul. 2016; N.P. Athukorala et al. leg.; beating; NIFS_SAL_888 • 1 ♂; Kandy District, NIFS premises; 600 m a.s.l.; 12 Mar. 2017; S.P. Benjamin leg.; hand collection; NIFS_SAL_1025 . – North Western Province • 1 ♂; Kurunegala District, Nikaravatiya; 1–3 Nov. 2007; Ziyard Jaleel leg.; hand collection; NIFS_SAL_506 .

Description

Male

MEASUREMENTS. TL 6.85, PL 2.58, PW at PLEs 2.31,AL 1.35,AW 0.87. Eye field: diameter of AME 0.28; ALE 0.18; PME 0.1; PLE 0.14; PME–PME 0.82; PLE–PLE 0.84; ALE–PME 0.32; ALE–PLE 0.42. Leg I: Tr 1, Fm 1.3, Pt 1.6, Tb 0.8, Mt 0.6; Leg II: Tr 1.12, Fm 1.1, Pt 1.06, Tb 0.7, Mt 0.42; Leg III: Tr 1.1, Fm 1.12, Pt 1.4, Tb 0.52, Mt 0.3; Leg IV: Tr 0.76, Fm 0.52, Pt 0.82, Tb 0.84, Mt 0.52.

COLOR AND BODY. Live spider with carapace robust and relatively broad, blackish-brown covered with long black hairs sparsely and two longitudinal stripes of white hairs (Fig. 2C–D). Sternum oval, brown; labium and maxillae yellowish brown, with paler outer margins. Clypeal region brownish; eyes surrounded by blackish orbital setae. Chelicerae brown with curved outer margins and excavated inner margins: two promarginal and one retromarginal teeth (Fig. 15B). Abdomen blackish brown, ovoid with two longitudinal belts of white hairs and entire surface covered with a few whitish hairs. Middorsum with four median beige spots in different shapes, covered with black scales; venter greyish with a blackish-brown median region covered with two broad whitish longitudinal bands. Spinnerets brown, covered with a patch of black hairs dorsally. Leg I robust; femora I–IV dark brown dorsally; patellae and tibiae dark brown; tarsi and metatarsi of all legs dark brown.

PALP. Dark brown; embolus short and thick with blunt tip; bulbus with PLP; RTA only slightly bent ventroapically, curved and claw-like (Figs 15E–F, 16A–B).

Female

MEASUREMENTS. TL 5.5, PL 2.04, PW at PLEs 1.95, AL 2.64, AW 2.16. Eye field: diameter of AME 0.48; ALE 0.26; PME 0.12; PLE 0.24; PME–PME 1.5; PLE–PLE 1.46; ALE–PME 0.44; ALE–PLE 0.78. Leg I: Tr 1, Fm 0.92, Pt 0.94, Tb 0.56, Mt 0.38; Leg II: Tr 1.2, Fm 0.78, Pt 1.1, Tb 0.7, Mt 0.46; Leg III: Tr 1.3, Fm 0.8, Pt 1.02, Tb 0.6, Mt 0.42; Leg IV: Tr 1, Fm 0.74, Pt 1.1, Tb 0.4, Mt 0.32.

COLOR AND BODY. Colouration pattern as in the male, but differs as follows: AMEs surrounded by yellow orbital setae; clypeus covered with white hairs; carapace with white longitudinal stripes (Fig. 15C).

EPIGYNUM. Structure of epigyne of C. viduus (Figs 15G, 16C–D) resembles that of C. taprobanicus but differs in relative proportions of spermathecae, rather elongated and globular in C. viduus (Fig. 16C–D), PEB more curved inwards by forming a prominent central curve, presence of a well-sclerotized midline, margins of CO well sclerotized and shape of CO more prominently C shaped than in C. taprobanicus (Fig. 15G).

Distribution and habitat

This species occurs in the mangrove forests in the arid zone and lowland secondary rainforests of the dry and wet zones of Sri Lanka (Fig. 17). Specimens were collected by beating vegetation up to a height of 1– 2 m.