Sesieutes apiculatus, Dankittipakul & Deeleman-Reinhold, 2013

Dankittipakul & Deeleman-Reinhold, 2013, Delimitation of the spider genus Sesieutes Simon, 1897, with descriptions of five new species from South East Asia (Araneae: Corinnidae), Journal of Natural History 47 (3), pp. 167-195 : 186-189

Sesieutes apiculatus sp. nov.

( Figures 1 I,J, 3 C, 8 A–E, 10 F)

Type material

Holotype. ♂, Indonesia, Pulau Belitung, Gunung Tajam, near Gurok Beraye Waterfall , 150 m, primary forest, 20 September 2008, leg. P.J. Schwendinger ( MHNG, IND–08 / 02) .

Paratypes. One ♀, data as holotype ( MHNG, IND–08 / 02) . 2♀, Indonesia, Pulau Belitung, Gunung Tajam, between Gurok Beraye Waterfall and summit, 150–450 m, primary forest, 21–26 September 2008, leg. P.J. Schwendinger ( MHNG, IND–08 / 03) . 1♀, Malaysia, Selangor State, Templer Park , 230–370 m, rainforest along stream, 13 July 2001, leg. P.J. Schwendinger ( MHNG, SIM–01 / 14) .

Diagnosis

Males and females of this new species can be easily recognized by the contrast body colour ( Figure 1I,J ), in which the punctated carapace is yellowish orange, the legs are bright yellow and the opisthosoma is dark greyish. Male palpal morphology is similar to that of S. lucens in having an apically situated conductor ( Figures 4 A, 8 A), but in this species the distal RTA is much shorter and its apex is sharply pointed (compare Figures 8 C and 4 C). Females can be easily distinguished from their congeners by the greatly elongated internal ducts with numerous coils (Figures 8 D,E, 10 F).

Etymology

The specific epithet is a Latinized adjective referring to the conductor of the male palp in relation to its position.

Description

Male (holotype). Total length 5.82; prosoma 2.76 long, 1.94 wide; opisthosoma 3.00 long, 1.74 wide. Leg measurements: leg I 7.60 (2.08, 2.78, 1.58, 1.18); II 6.48 (1.72, 2.34, 1.38, 1.04); III 5.50 (1.58, 1.56, 1.38, 0.96); IV 8.40 (2.20, 2.62, 2.34, 1.24). Leg spination. Leg I: Fe p–1, Ti v–2–2 –2–2–2–2, Mt v–2–2 –2; leg II: Ti v–2–2 –2–2–2–2, Mt v–2–2 –2; leg III: Ti p–1 v–1–1 –1–2 r–1, Mt p–1 v–1–1 r–1; leg IV: Fe d–0–1, Ti v–1–1 –1–2 r–1, Mt p–1, v–1–1 –1–1, r–1–1.

Pattern and coloration ( Figure 1I) . Carapace brown, with dark circular ring; integument punctated, punctures shallow, forming radiating striae; chelicerae, labium and gnathocoxae brown; sternum dark brown; legs yellow, anterior femora and tibiae slightly darker than other leg segments. Opisthosoma ovoid; dorsum dark grey; venter pale; dorsal scutum yellow, lightly sclerotized, occupying three-quarters of length of opisthosoma; spinnerets white.

Palp ( Figures 3 C, 8 A–C). Palpal tibia with small, triangular prolateral excrescence; proximal RTA truncated, with narrowed membranous area situated apically in ventral view, elevated triangular projection with subspherical base in prolateral view; distal RTA heavily sclerotized, triangular, relatively short, apex sharply pointed; tegulum more or less triangular, with deep apico-prolateral excavation and baso-prolateral enlargement; conductor lanceolated, gradually tapering anteriorly, originating on apical portion of tegulum; tegular apophysis spiniform, hyaline, originating near base of conductor; embolic base originating apico-prolaterally.

Female (paratype, MHNG). Total length 5.80; prosoma 2.90 long, 2.00 wide; opisthosoma 3.10 long, 1.82 wide. Leg measurements: leg I 7.96 (2.18, 2.90, 1.66, 1.24); II 6.80 (1.80, 2.46, 1.44, 1.08); III 5.78 (1.66, 1.62, 1.44, 1.02); IV 8.84 (2.32, 2.76, 2.46, 1.30).Leg spination. Leg I: Fe p–1, Ti v–2–2 –2–2–2–2–2, Mt v–2–2 –2–2–2; leg II: Ti v–2–2 –2–2–2–2, Mt v–2–2 –2–2 r–1; leg III: Ti p–1 v–2–1 –1–1 r–1, Mt p–1 v–1–1 r–1; leg IV: Fe d–0–1, Ti v–2–1 –1–1 r–1, Mt p–1–1 v–2–1 –1, r–1–1.

Pattern and coloration ( Figure 1J) . Carapace brown, with dark pigment forming circular ring encircling depressed fovea; integument punctated, punctures shallow and minute; chelicerae, labium and gnathocoxae brown; sternum dark brown; legs yellow. Opisthosoma ovoid, widest posteriorly; dorsum dark grey; venter pale; dorsal scutum yellow, lightly sclerotized, occupying half length of opisthosoma; spinnerets white.

Genitalia ( Figures 8 D,E, 10 F). Epigastric scutum weakly sclerotized, with pair of circular copulatory orifices situated posteriorly; proximal ducts elongated, ascending anteriorly and curving posteriorly; insemination ducts intertwined, descending posteriorly then ascending anteriorly, forming six to seven coils; spermathecae elliptical, with large circular gland pores situated anteriorly.

Natural history

Sesieutes apiculatus sp. nov. inhabits evergreen rainforests on a small island.

Distribution

Known only from the type locality, an island off Sumatra.

Figures

Figure 1. Sesieutes spp., dorsal habitus (A – O). Sesieutes lucens Simon, male (A), female (B). Sesieutes minuatus sp. nov., holotype male (C), paratype female (D). Sesieutes abruptus sp. nov., holotype male (E), paratype female (F). Sesieutes bifidus sp. nov., holotype male (G), paratype female (H). Sesieutes apiculatus sp. nov., holotype male (I), paratype female (J). Sesieutes aberrans sp. nov., holotype male (K). Sesieutes sp. from Vietnam, male (L). Sesieutes sp. from Laos, male (M). Sesieutes borneensis Deeleman-Reinhold, male from Palawan (N). Sesieutes sp. from southern Thailand, female (O). Scale bar 1. 0 mm.

Figure 3. Sesieutes spp., male palp, retrolateral view (A – C, G, I – L), ventral view (D, E), dorsal view (F, H). Sesieutes bulbosus Deeleman-Reinhold, holotype (A); Sesieutes borneensis Deeleman-Reinhold, holotype (B); Sesieutes apiculatus sp. nov., holotype (C); Sesieutes lucens Simon, holotype (D); Sesieutes abruptus sp. nov., holotype (E, F); Sesieutes scrobiculatus Deeleman-Reinhold, holotype (G, H); Sesieutes aberrans sp. nov., holotype (I); Sesieutes nitens Deeleman-Reinhold, holotype (J); Sesieutes emancipatus Deeleman-Reinhold, holotype (K); Sesieutes minuatus sp. nov., holotype (L). Scale bar 0. 1 mm.

Figure 10. Sesieutes spp., epigyne, ventral view. Sesieutes minor Deeleman-Reinhold, paratype (A); Sesieutes scrobiculatus Deeleman-Reinhold, paratype (B); Sesieutes nitens Deeleman- Reinhold, paratype (C); Sesieutes bulbosus Deeleman-Reinhold, paratype (D); Sesieutes emancipatus Deeleman-Reinhold, paratype (E); Sesieutes apiculatus sp. nov., paratype (F); Sesieutes bifidus sp. nov., paratype (G); Sesieutes borneensis Deeleman-Reinhold, paratype (H); Sesieutes lucens Simon, female from Malaysia (I).