Sesieutes abruptus, 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 : 182-184

Sesieutes abruptus sp. nov.

( Figures 1 E,F, 3 E,F, 6 A–F)

Type material

Holotype. ♂, Malaysia, Pahang State, Tioman Island , 100 m, 26 June 2001, leg. A. Schulz and K. Vock ( MHNG, M01–41) .

Paratypes. One ♂, 1♀, data as holotype ( MHNG, M01–4) . Malaysia, Pahang State, Tioman Island: 1♂, 160 m, rainforest, 2 October 2001, leg. L. Monod ( MHNG, TM– 17) ; 2♂, 1♀, 100 m, 26 June 2001, leg. A. Schulz and K. Vock ( MHNG, M01–41) ; 2♀, footpath from Tekek to Juara , 240–300 m, disturbed rainforest, 29 June 2001, leg. P.J. Schwendinger ( MHNG, SIM–01 / 08) ; 1♂, 2♀, west side of Mt Kajang, 2 km east of Kg. Genting , 400 m, 2 July 2001, leg. A. Schulz and K. Vock ( MHNG, M01–107) ; 1♂, 1♀, 100 m, 26 June 2001, leg. A. Schulz and K. Vock ( MHNG, M01–41) ; 1♂, 500 m, 26 June 2001, leg. A. Schulz and K. Vock ( MHNG, M01–43) ; 1♂, path from Kg. Paya to Gunnung Kajang , 200–600 m, 6–7 June 2007, leg. A. Schulz ( MHNG, AS–WM–07 / 7) .

Diagnosis

Sesieutes abruptus sp. nov. closely resembles that of S. lucens in general appearance (compare Figures 1E with 1A, and 1F cf. 1B). Males share with those of S. lucens , S. borneensis and S. bulbosus an elongated, heavily sclerotized distal RTA of the male palp, but can be distinguished by the subterminally, abruptly bent apex ( Figure 3E,F ), and by the distinctly shorter, anteriorly situated conductor ( Figure 3E ). Females resemble those of S. bifidus sp. nov. in having anteriorly located copulatory orifices and funnel-shaped proximal ducts ( Figure 6D,E ), but can be distinguished by their simple insemination ducts ( Figures 6E,F ).

Etymology

The specific epithet refers to the abruptly bent apex of the distal retrolateral tibial apophysis on the male palp.

Description

Male (holotype). Total length 4.24; prosoma 2.12 long, 1.48 wide; opisthosoma 2.50 long, 1.32 wide. Leg measurements: leg I 5.84 (1.58, 2.12, 1.22, 0.90); II 4.98

(1.32, 1.80, 1.06, 0.80); III 4.22 (1.21, 1.20, 1.06, 0.74); IV 6.46 (1.68, 2.02, 1.80, 0.96).

Leg spination. Leg I: Fe d–1 p–1, Ti v–2–2 –2–2–2–2–2, Mt v–2–2 –2–2; leg II: Ti v–2–2 –2–2–2–2–2, Mt v–2–2 –2–2; leg III: Ti v–1–2 –2, Mt v–1–1 –2; leg IV: Fe d–1, Ti v–1–2 –2 r–1, Mt p–1, v–1–2, r–1.

Pattern and coloration ( Figure 1E ). Carapace brown; integument strongly granulated, granules minute, each with short setae; chelicerae, labium and gnathocoxae orange-brown; sternum dark brown; legs bicolored, coxae to femora orange-brown, patellae to tarsi yellow, distal half of femora I and IV yellow distally. Opisthosoma ovoid, widest posteriorly; dorsum pale grey; venter pale; dorsal scutum orange-brown, occupying three-quarters length of opisthosoma; spinnerets white.

Palp ( Figures 3 E,F, 6 A–C). Palpal tibia with digitiform prolateral excrescence; proximal RTA truncated, represented by elevated ridge with broad membranous apex in ventral view, more or less triangular in lateral view; distal RTA heavily sclerotized, elongated, triangular, apex subterminally abruptly bent ectad; conductor lanceolated, base rather broad, originating on mid-apical portion of tegulum; tegular apophysis spiniform, hyaline, originating near base of conductor.

Female (paratype, MHNG). Total length 4.36; prosoma 2.18 long, 1.52 wide; opisthosoma 2.48 long, 1.38 wide. Leg measurements: leg I 5.98 (1.62, 2.18, 1.24, 0.92); II 5.12 (1.36, 1.84, 1.10, 0.80); III 4.34 (1.26, 1.23, 1.09, 0.76); IV 6.64 (1.74, 2.06, 1.84, 0.98). Leg spination. Leg I: Fe d–1 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, Mt v–2–2 –2–2; leg III: Ti p–1 v–1–1 –1–1, Mt p–1–1 v–1–1 r–1; leg IV: Ti p–1–1 v–1–1 –1–1 r–1, Mt p–1–1, v–1–1, r–1.

Pattern and coloration ( Figure 1F ). Carapace reddish brown; integument strongly granulated, granules minute; chelicerae, labium and gnathocoxae orange-brown; sternum brown; legs bicolored, coxae to femora orange-brown, patellae to tarsi yellow, distal half of femora I and IV yellow distally, tibiae III and IV with median band of dark green. Opisthosoma ovoid; dorsum pale grey; venter pale; dorsal scutum orangebrown, semi-circular, occupying one-third length of opisthosoma, followed by pair of muscle apodemes and seven pale chevrons; spinnerets white.

Genitalia ( Figure 6D–F ). Copulatory orifices teardrop-shaped, situated anteriorly, connected to funnel-shaped proximal ducts; insemination ducts short, obliquely arranged; spermathecae elliptical, situated posteriorly, each with anteriorly situated, circular gland opening; fertilization ducts elongated, acicular.

Natural history

Types of S. abruptus sp. nov. were collected by sifting decomposing organic litter in evergreen rainforests.

Distribution

Known only from Tioman Island, 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 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 6. Sesieutes abruptus sp. nov. Holotype, male palp (A – C), ventral view (A), prolateral view (B), retrolateral view (C). Paratype, female (D – F), epigyne, ventral view (D), internal genitalia, dorsal view (E, F). Scale bars 0. 1 mm (A – C); 0. 2 5 mm (D – F).