Opadometa sarawakensis Dzulhelmi et Suriyanti, 2015

Dzulhelmi, Muhammad Nasir, Suriyanti, Su, Zulqarnain, Mohamed & Norma, Che Yusoff, 2015, Two new Opadometa species (Araneae: Tetragnathidae) from Sarawak, Malaysia, Annales Zoologici 65, pp. 101-107 : 102-103

Opadometa sarawakensis Dzulhelmi et Suriyanti sp. nov.

Etymology. The specific name is a noun, referring to the state of the location where the holotype was collected.

Diagnosis. The O. sarawakensis resembles as O. kuchingensis but differed in the following: Epigyne: (1) The spermathecae shape for O. sarawakensis is oblong as in bean-like shape, while O. kuchingensis are ovate as mushroom-like shape, and O. grata are rectangular-like in shape. Body colouration: (2) The O. sarawakensis has red oval patch on the dorsal abdomen while the blue colouration with black markings covering other part of the abdomen, while O. fastigata and O. kuchingensis has reddish-orange colouration.

DDescription. Female. Total length 9.05; Carapace: 3.57 long, 2.54 wide; carapace dark-brown in colour, carapace longer than wide, cephalic area markedly narrower than thoracic area, sternum darker brown in colour and slightly longer than wide in length, 1.44 long, 1.42 wide ( Fig. 7 ). The thoracic area is wider and lower than the cephalic area. Eyes: Diameters AME 0.14, ALE 0.12, PME 0.13, PLE 0.12; inter-distances AME–AME 0.18, AME–ALE 0.47, PME–PME 0.15, PME– PLE 0.44, PLE-PLE 0.10, AME–PME 0.21; clypeus 0.15 high. Lateral eyes loosely contiguous or almost so, eight eyes slightly recurved in two rows ( Figs 5, 6 ). The AME is slightly bigger than PME. PME slightly shorter than AME, distance between PME slightly shorter than between AME, PME size greater than distance between them, AME size about the same as distance between them, distance between PME and PLE are about three and a half times the PME eye size. Chelicerae: Promargin with series of 4 teeth, retromargin with series of 4 teeth ( Figs 10, 11 ). Abdomen: abdomen 8.57 long, 5.10 width; Pear-shaped pointed forward abdomen overhanging the carapace, blue colour covering the abdomen and some black markings on the abdomen with a red coloured oval patch at the middle part of the abdomen ( Figs 8, 9 ). Spinnerets: Spinnerets at ventral tip of the abdomen, tip of spinneret facing downward and does not exceed end of abdomen. Legs: The legs are dark brown in colour with black annulations, leg formula (I–II–IV–III), leg measurements (femur/ patella/ tibia/ metatarsus/ tarsus/ total): leg I (4.58/1.25/ 4.16/5.56/1.81/17.36), leg II (4.72/1.32/4.31/4.16/1.52/ 16.03), leg III (2.78/0.83/1.53/2.22/0.97/8.33), and leg IV (4.17/1.20/3.29/4.44/1.53/14.63). Short spines on legs, Leg I: femur I with 1–3 spines, tibia I with no spines, dense brush of hairs covering more than one-third of the tibia; Leg II: femur II with no spines, tibia II with 3–4 spines, very few brush hairs covering more than one-third of the tibia, one row of long trichobothria covering one-third of retrolateral femur II; Leg III: femur III with 1–2 spines, tibia III with 3–4 spines, one row of short trichobothria covering more than two third of prolateral femur III; Leg IV: femur IV with 1–3 spines, tibia IV with 1–3 spines, thick brush of hairs covering more than one-third of the tibia, two rows of long trichobothria covering more than two third of the prolateral femur IV. Epigyne: Simple and weakly sclerotized, spermathecae oblong and bean-like in shape, copulatory duct and spermathecae almost equal in length ( Figs 12, 13 ).

Male. Unknown.

Type material. Female holotype ( BNP003 ) from Bako National Park, Sarawak, Malaysia (1°41’N, 110°26’E) was collected by hand picking (Collector: Suriyanti Su) during daytime at 1315 hours on 26th April 2013 .

Distribution. It is known from the type locality at the lowland dipterocarp forest in Sarawak. Similar species was also recorded from wooded areas and disturbed forest in Brunei ( Koh and Ming 2013), and Maliau Basin, Sabah. It is likely to be found in Borneo rainforest.

Natural history. Diurnal. The spider was found resting at the center of its web during daylight. The webs were constructed at 30° angle between two trees in an open space above 200 cm from the ground which was covered with dead leaves.

Figures

Figures 5–13. Female Opadometa sarawakensis new species. Eye pattern: (5) dorsal view, (6) frontal view; female body: (7) ventral view, (8) dorsal view, (9) lateral view; right teeth: (10) inner view, (11) lateral view; epigyne: (12) dorsal view (internal), (13) ventral view (outer).