Sesieutes bifidus, 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 : 184-186

Sesieutes bifidus sp. nov.

( Figures 1 G,H, 7 A–E, 10 G)

Type material

Holotype. ♂, Malaysia, Pahang State, Cameron Highland, Tanah Rata, Mt Jasar , 1700 m, sifting leaf litter, 18 April to 11 May 2009, leg. P. Banar ( MHNG, WM–1) .

Paratypes. One ♀, Cameron Highland, Tanah Rata , 470–1550 m, sifting leaf litter and rotten wood, 25 April to 15 May 2009, leg. P. Banar ( MHNG, 2) .

Diagnosis

Male of S. bifidus sp. nov. can be easily recognized by the bifid distal RTA of the male palp ( Figure 7C ). Females closely resemble those of S. abruptus sp. nov., but can be distinguished by the more elongated insemination ducts provided with one additional coil (compare Figures 7 E and 6 E).

Etymology

The specific epithet is a Latinized adjective referring to a bifid distal RTA of the male palp.

Description

Male (holotype). Total length 6.40; prosoma 3.20 long, 2.26 wide; opisthosoma 3.60 long, 2.20 wide. Leg measurements: leg I 8.80 (2.40, 3.20, 1.84, 1.36); II 7.52 (2.00, 2.72, 1.60, 1.20); III 6.36 (1.84, 1.80, 1.60, 1.12); IV 9.76 (2.56, 3.04, 2.72, 1.44). 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, Mt v–2–2 –2; leg III: Ti p–1 v–2–2 –1 r–1, Mt p–1 v–2–2 –1 r–1; leg IV: Fe d–0–1, Ti v–2–2 –2 r–1, Mt p–1, v–1–1 –1–1, r–1.

Pattern and coloration ( Figure 1G ). Carapace reddish brown, with dark marking forming striae; integument smooth; fovea indistinct, replaced by shallow, longitudinal depression; chelicerae, labium and gnathocoxae yellowish brown; sternum brown, margin and extensions dark brown; legs orange, anterior femora and tibiae slightly darker than other segments. Opisthosoma ovoid; dorsum grey; venter pale; dorsal scutum ovoid, heavily sclerotized, occupying three-quarters of length of opisthosoma.

Palp ( Figure 7A–C ). Palpal tibia with digitiform prolateral excrescence; proximal RTA truncated, with membranous anterior surface, triangular with subspherical base in prolateral view, rectangular in retrolateral view; distal RTA heavily sclerotized, cylindrical, apex bifid, with sharply pointed basal tooth and blunt apical tooth; tegulum more or less spherical in ventral view, deeply excavated apico-prolaterally; conductor lanceolated, gradually tapering anteriorly, originating on anterior portion of tegulum; tegular apophysis spiniform, hyaline, originating near base of conductor; embolic base originating on apical portion of tegulum.

Female (paratype, MHNG). Total length 6.30; prosoma 3.00 long, 2.10 wide; opisthosoma 3.30 long, 1.68 wide. Leg measurements: leg I 8.25 (2.25, 3.00, 1.72, 1.26); II 7.04 (1.86, 2.54, 1.50, 1.12); III 5.98 (1.72, 1.68, 1.50, 1.06); IV 9.14 (2.40, 2.84, 2.54, 1.36). Leg spination. Leg I: Fe d–1 p–1, Ti v–2–2 –2–2 + pv–1, Mt v–2–2 –2; leg II: Ti v–2–2 –2–2, Mt v–2–2 –2; leg III: Ti p–1 v–2–2 –1 r–1, Mt p–1– 1 v –1 r–1; leg IV: Ti d–1 p–1 v–2–2 r–1–1, Mt p–1 v–1–2 r–1.

Pattern and coloration ( Figure 1H ). Carapace yellowish brown, with dark striae; integument smooth; fovea indistinct, represented by shallow depression; chelicerae, labium and gnathocoxae brown; sternum yellow, with dark brown margin; legs yellow, except anterior femora slightly darker than other leg segments. Opisthosoma elongateovoid; dorsum pale grey; venter pale; dorsal scutum orange-brown, semi-circular, occupying one-fifth length of opisthosoma; spinnerets white.

Genitalia ( Figures 7 D,E, 10 G). Epigastric scutum weakly sclerotized, with narrowed, spatulate-shaped copulatory orifices situated anteriorly; proximal ducts funnelshaped, very broad, lateral margin straight; insemination ducts short, forming one or two coils; spermathecae reniform, gland pores situated more or less posteriorly.

Natural history

Sesieutes bifidus sp. nov. inhabits a remnant patch of evergreen hill forests on Cameron Highland mountainous resort where most of the area is cultivated land.

Distribution

Known only from the type locality in Malaysia.

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 7. Sesieutes bifidus sp. nov. Holotype, male palp (A – C), ventral view (A), prolateral view (B), retrolateral view (C). Paratype, female (D, E), epigyne, ventral view (D); internal genitalia, dorsal view (E). Scale bars 0. 1 mm (A – C); 0. 2 5 mm (D, E).

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).