Sudharmia tridenticula, Dankittipakul & Deeleman-Reinhold, 2012

Dankittipakul & Deeleman-Reinhold, 2012, A new spider species of the genus Sudharmia from Sumatra, Indonesia (Araneae, Liocranidae), Zoological Research 33 (2), pp. 187-190 : 188-189

2.1 Sudharmia tridenticula sp. nov. （ Fig. 1 a −e）

Type material: Holotype ♂, Indonesia, Sumatra, West Sumatra Province, Batang Palupuh Rafflesia Sactuary , 12 km north of Bukittinggi , S00º14′32″, E100º21′10″, 900−1 0 0 0 m, primary forest, June 2nd–3rd, 2006, P.J. Schwendinger leg. ( MHNG, Sum–06/05) .

Paratypes: 1♂, 1♀, data as holotype ( MHNG, Sum– 06/05) ; 4♂, 2♀, West Sumatra Province, Rimbo Panti Nature Reserve , ca. 30 km north of Lubuksikaping , N0°20′46′′, E100°04′09′′, 300− 400 m, primary forest, June 11th −13th 2006, P.J. Schwendinger leg. ( MHNG, Sum–06/18).

Etymology: The specific epithet is derived from a combination of Latin words (tri =three; denticulus =with denticles), and refers to three apophyses on the male palpal patella and tibia.

Diagnosis: Males of this S. tridenticula sp. nov. can be distinguished from those of S. beroni Deeleman- Reinhold, 2001 and S. pongorum Deeleman-Reinhold, 2001 by the hook-shaped subapical extension on the embolus ( Fig.1 b,c; additional extension absent in those of S. beroni and S. pongorum ), and by the presence of a short apophysis on the palpal patella ( Fig.1 b,c, PA) and two longer ones on the palpal tibia ( Fig.1 b,c, PTA and DTA) (a patellar apophysis is absent and only a single retrolateral tibial apophysis is present in those two species). Females can be easily distinguished by the internal ducts running mid-longitudinally ( Fig. 1 d −e) (median ducts short and indistinct in those of S. beroni and S. pongorumi).

Description: Male (holotype): Total length 2.26; prosoma 1.26 long, 0.84 wide; opisthosoma 1.40 long, 1.04 wide. Leg formula 4123. Leg measurements. I 4.75 (2.13, 1.43, 0.70, 0.49), II 3.30 (0.93, 1.20, 0.66, 0.49), III 2.58 (0.71, 0.77, 0.60, 0.49), IV 4.30 (1.10, 1.66, 0.88, 0.66). Spination. Leg I: femur pr-1, tibia v-2-2 -2-2-2-2-2, metatarsus v-2-2; leg II: femur d-1; tibia pv-2-2-2-2-2; metatarsus v-2-2; leg IV femur d-1.

Prosoma anteriorly narrowed, widest between coxae II, in profile highest just in front of deep, longitudinal fovea. Carapace brown, with black fovea and dark brown pattern; integument finely punctated. Sternum convex, yellowish brown. Legs yellowish, except femora I & II dark brown. Femora I & II enlarged. Metatarsi III & IV apically with preening brush. Eye subequal in size, circular, clear, except AME dark, encircled with black ring; AER straight; PER slightly recurved, wider than AER. Opisthosoma ovoid; dorsum dark grey, posteriorly with three pale transverse median chevrons; dorsal scutum coriaceous, rectangular, its anterior margin narrower than posterior one, occupying approximately 1/3 opisthosomal length; venter pale, without pattern.

Palp ( Fig.1 a −c). Femur medially with deep, semicircular excavation. Patella provided with triangular, sharply pointed retrolateral apophysis. Tibia more or less cylindrical in ventral view, slightly excavated medially in lateral view; RTA absent; proximal tibial apophysis (PTA) digitiform, apically rounded, directed anteriad; distal tibial apophysis (DTA) cylindrical, apex elongated, sharply pointed, directed dorsad. Tegulum elongateovoid, subapically with slightly elevated triangular, medially situated hump. Sperm duct thin, encircling tegulum, forming two loops. Tegular apophysis lanceolated, hyaline, semi-transparent, originating subapically, apex reaching half length of embolus. Embolus situated apically, sigmoid-shaped in ventral view, heavily sclerotized, with hook-shaped subterminal extension.

Female (paratype): total length 2.42; prosoma 1.10 long, 0.94 wide; opisthosoma 1.32 long, 1.12 wide. Leg formula 4123. Leg measurements. I 3.51 (0.94, 1.36, 0.72, 0.47), II 3.15 (0.88, 1.15, 0.64, 0.48), III 2.46 (0.68, 0.72, 0.56, 0.48), IV 4.08 (1.04, 1.57, 0.84, 0.62). Spination. Leg I: femur pr-1, tibia v-2-2 -2-2-2-2-2, metatarsus v-2-2; leg II: femur d-1; tibia pv-2-2-2-2-2; metatarsus v-2-2 -2; leg IV femur d-1.

Coloration and pattern. General appearance as in male but PME smallest; legs brown, distal part distinctly paler than proximal part, almost yellow; opisthosoma pale, lacking distinctive pattern; dorsal scutum absent.

Genitalia ( Fig.1 d,e). Epigynal region with shallow lateral depressions obliquely situated; posterior margin excavated and provided with triangular median extension. Internal genitalia represented by simple duct system consisting of tubular ducts running mid-longitudinally, posterior part extending laterally to form simple coils and terminally enlarged spermathecae. Fertilization ducts acuminated.

Natural history: Types of S. tridenticula sp. nov. were collected by sifting decomposed organic litter in primary evergreen forests (300−1 0 0 0 m).

Distribution: Indonesia (West Sumatra Province).

3 Discussion

The genus Sudharmia was originally established for two liocranid spiders confined to humid, primary evergreen forests of Sumatra. The genus currently includes 3 species: S. beroni , S. pongorum , and S. tridenticula sp. nov. All species occur in the mountainous regions of West Sumatra.

Of interest is the modification of the proximal and distal apophyses on the retrolateral side of the male palpal tibia, in addition to the possession of a patellar apophysis and a deep retrolateral excavation of femora. These apophyses are rather long, and enlarged ( Fig.1 c), and it is reasonable to assume that they perform some clasping function during mating. Males with these modified apophyses ( S. tridenticula sp. nov. and S. pongorum ) also have some forms of modification on their femora, usually represented by an elevated ridge or a depression on the ventro-distal surface. These palpal modifications bear close resemblance to the males of Otacilia . However, males of Sudharmia can be easily distinguished by the enormously enlarged embolus, while the embolus is generally represented by a small, spiniform sclerite in those of Otacilia .

Figures

Fig. 1 The illustrations of Sudharmia tridenticula sp. nov. a-c) male holotype; d-e) female paratype; a) left male palp, prolateral; b) ditto, retrolateral; c) ditto, ventral (slightly tilt); d) epigyne, ventral; e) internal genitalia, dorsal