Sarax bilua Miranda & Giupponi & Prendini & Scharff 2021, sp. nov.

Sarax bilua sp. nov.

urn:lsid:zoobank.org:act: 459C6DC3-F213-40BB-A67B-3F4B0A048074

Figs 103, 105–107; Table 8

Diagnosis

This species may be separated from other species of Sarax in Southeast Asia and Oceania by the following combination of characters: chelicera without retrolateral tooth on basal segment opposite to bifid tooth; cheliceral claw with three teeth; pedipalp femur with four or five dorsal spines and four or five ventral spines (Fig. 105E–F); pedipalp patella with three dorsal spines and two ventral spines (Fig. 105E–F); leg IV basitibia with four pseudo-articles and trichobothrium bt situated distally; distitibia trichobothrium bc situated closer to bf than to sbf; sc and sf series each with five trichobothria.

This species resembles S. sarawakensis, but possesses fewer teeth on the cheliceral claw and more spines on the pedipalp femur.

Etymology

The species name is a noun in apposition, taken from bilua, the most common Papuan language spoken in the Solomon Islands, by the people on the island of Vella Lavella.

Type material

Holotype SOLOMON ISLANDS • ♀; Western Province, Vella Lavella Island, MBuna Poro Village; 7°45′31.56″ S, 156°39′55″ E; 25 Oct. 2004; C. Sirno, R. Wys and L. Monod leg.; rainforest, under rotten log; AMCC [LP 5564].

Paratypes SOLOMON ISLANDS • 3 ♀♀; same collection data as for holotype; AMCC [LP 5564].

Description

CARAPACE. Six anterior setae (Fig. 105A, C); frontal process triangular (Fig. 105C). Small granules densely scattered between ocular triads and among sulci. Median eyes well developed (Fig. 105A, C); median ocular tubercle reduced; pair of setae on median ocular tubercle; lateral eyes well developed, seta lateral to lateral ocular triad; lateral ocular triad near carapace margin; curved carina between ocular triads and lateral margin of carapace (Fig. 105C).

STERNUM. Tritosternum anteriorly projected with typical setation (Fig. 105B); other sternal platelets narrow and concave, with pair of setae anteriorly on plaque and some smaller setae posteriorly; pentasternum four setae anteriorly and without seta on membranous region.

OPISTHOSOMA. Ventral sacs and ventral sac cover present.

GENITALIA. Female genital operculum with prominent setae posteromedially and some smaller setae near margin, without bulges medially (Fig. 106A–C); gonopod with pair of short, plunger-like submedian lobes unsclerotized basally (Fig. 106A, C, F); denticulate surface between gonopod and posterior margin of genital operculum (Fig. 106D); slit sensilla on lateral margin of genital operculum (Fig. 106E). Male unknown.

CHELICERAE. Basal segment without tooth on retrolateral surface, opposite to bifid tooth; retrolateral surface of claw with continuous row of setae, basally to medially; claw with three teeth; row of around ten setae on prolateral surface of basal segment; bifid tooth on basal segment with dorsal cusp larger than ventral cusp.

PEDIPALPS. Coxae with seta encircled by round carina and three setae on margin. Femur with four or five dorsal spines and four or five ventral spines (Fig. 105E–F); long spine between ventral spine 1 and proximal margin; three prominent setiferous tubercles between dorsal spine 1 and proximal margin. Patella with three dorsal spines in primary series (Fig. 105E); prominent setiferous tubercle distal to dorsal spine I, one-third length of spine I; two prominent setiferous tubercles proximal to dorsal spine III; two ventral spines; long setiferous tubercle proximal to spine II and prominent setiferous tubercle between spine I and distal margin. Tibia with ventral spine distally and three or four setae between spine and distal margin. Tarsus with one dorsal spine, one-fifth length of tarsus (Fig. 105D); cleaning organ with 30 setae in ventral row.

LEGS. Tibia of leg I with 23 articles; tarsus I with 41 articles; tarsal organ situated near base of claw (Fig. 107A–C); rod sensilla with four setae in shallow groove (Fig. 107D); first tarsal article similar in length to second article. Leg IV basitibia with four pseudo-articles, without sclerotized, denticulate projection at apex of articles; trichobothrium bt situated in distal third of pseudo-article; distitibia trichobothrium bc situated closer to bf than to s bf; sc and sf series each with five trichobothria.

Measurements

See Table 8.

Distribution

Known only from the type locality.

Natural history

The three ovigerous females are different sizes, suggesting different developmental stages. The small female does not appear to be a fully developed adult and the possession of eggs at an early stage of development suggests this species may be parthenogenetic.