Arnapa tolire Huber, 2019

Huber, Bernhard A. & Carvalho, Leonardo S., 2019, Filling the gaps: descriptions of unnamed species included in the latest molecular phylogeny of Pholcidae (Araneae), Zootaxa 4546 (1), pp. 1-96 : 22-24

Arnapa tolire Huber sp. n.

Figs 41–42 , 60–64 , 73 , 84–86 , 90–94

Gen.n. Ind117: Eberle et al. 2018 (molecular data); Huber et al. 2018: fig. 2.

Type material. INDONESIA: ♂ holotype, ZFMK ( Ar 20611), Ternate , at Danau (Lake) Tolire (0.830°N, 127.311°E), 180–220 m a.s.l., 12.xi.2009 (S. Sutono) .

Other material examined. INDONESIA: 5♂ 11♀, ZFMK (Ar 20612–13) and 1 juv. in pure ethanol, ZFMK (Ind209), same data as holotype .

Etymology. The species name is derived from the type locality; noun in apposition.

Diagnosis. Distinguished from known congeners by armature of male chelicerae ( Fig. 63 ; ~3–4 large lateral apophyses plus proximal patch of 3–4 smaller apophyses), by more slender palpal segments in general ( Figs 60– 61 ) and procursus in particular, the latter with distinctive prolateral sclerite distally ( Fig. 62 ; with pointed side branch), by shape of bulbal process ( Fig. 64 ), by shape of epigynum ( Figs 84 , 94 ; pair of anterior areas with strong transversal ridges and pair of rounded posterior projections), and by elongate pore plates ( Figs 73 , 86 ).

Description. Male (holotype). MEASUREMENTS. Total length 2.1, carapace width 0.95. Distance PME-PME 75 µm; diameter PME 85 µm; distance PME-ALE 60 µm; distance AME-AME 15 µm, diameter AME 40 µm. Leg 1: 24.6 (5.9 + 0.4 + 6.1 + 10.2 + 2.0), tibia 2: 3.4, tibia 3: 2.4, tibia 4: 3.3; tibia 1 L/d: 81.

COLOR (in ethanol). Carapace ochre-yellow with dark brown bands laterally and wide band medially including ocular area; clypeus with pair of dark bands below eye triads; sternum ochre-yellow with pair of light brown bands on both sides of median line; legs brown, with indistinct darker rings on femora (subdistally) and tibiae (proximally and subdistally), tips of femora and tibiae whitish. Abdomen gray, dorsally densely covered with dark marks, ventrally with large brown mark in front of gonopore, dark median band behind gonopore, pair of brown external marks and pair of larger internal ventro-lateral marks in front of spinnerets.

BODY. Habitus as in Fig. 41 . Ocular area elevated, thoracic furrow present; clypeus unmodified. Sternum wider than long (0.58/0.36), unmodified.

CHELICERAE. As in Fig. 63 , each side with 3–4 large sclerotized cones along lateral margin and 3–4 smaller cones frontally proximally; without modified hairs; with stridulatory ridges.

PALPS. As in Figs 60–61 ; coxa unmodified, trochanter ventrally only slightly protruding, femur widened, with rounded retrolateral process proximally, with prolateral stridulatory pick (modified hair) proximally and stronger than usual hairs distally on ventral-retrolateral side, patella ventrally reduced (not closed), tibia longer than in known relatives, retrolateral trichobothrium in very proximal position, tarsus small, procursus with dorsal process proximally, ventrally without pocket, distally with distinctive sclerotized and membranous elements ( Fig. 62 ); genital bulb large, with complex process ( Fig. 64 ).

LEGS. Without spines, few vertical hairs; with curved hairs on tibiae and metatarsi 1–2 (few on legs 2); retrolateral trichobothrium of tibia 1 at 11%; prolateral trichobothrium present on all tibiae; tarsus 1 with ~30 pseudosegments, distally distinct.

Male (variation). Size and number of sclerotized cones on chelicerae slightly variable but pattern consistent. Tibia 1 in 5 other males: 5.2–6.1 (mean 5.7).

Female. In general similar to male ( Fig. 42 ), also with curved hairs on legs. Chelicerae without stridulatory ridges ( Fig. 92 ). Tibia 1 in 9 females: 3.8–4.6 (mean 4.1). Palpal tarsal organ exposed ( Fig. 93 ). Epigynum anterior plate square-shaped ( Figs 84 , 94 ), with two areas of deep transversal ridges anteriorly laterally, medially whitish, posterior rim with pair of rounded projections; with separate brown plate in front of epigynum; posterior plate very short but wide. Internal genitalia with distinctive lateral folds, narrow anterior ‘valve’, and elongated pore plates ( Figs 73 , 86 ). ALS with only two spigots each (confirmed by SEM).

Distribution. Known from type locality only ( Fig. 343 ).

Natural history. The spiders were found in a degraded forest in a ravine leading into the lake; their domed webs were built among rocks near the ground and under large dead palm leaves lying on the ground.

Figures

FIGURE 343. Known distribution of Arnapa gen. n.; red marks: undescribed species. Further undescribed species that might belong in this genus are known from the Caroline Islands and from Papua New Guinea east to the Louisiade Archipelago.

FIGURES 39–44. Arnapa spp., live specimens. 39–40. A. arfak sp. n., male and female from Mokwam. 41–42. A. tolire sp. n., male and female with egg sac from Ternate. 43–44. A. tinoor sp. n., male and female from near Tomohon.

FIGURES 60–64. Arnapa tolire sp. n. (ZFMK, Ar 20612). 60–61. Left male palp, prolateral and retrolateral views. 62. Left procursus, dorsal view. 63. Male chelicerae, frontal view. 64. Left genital bulb, dorsal view. Scale lines: 0.3 (63), 0.5 (60–62, 64).

FIGURES 70–74. Arnapa spp., cleared female genitalia, dorsal views. 70. A. arfak sp. n. (ZFMK, Ar 20605). 71. A. manokwari sp. n. (ZFMK, Ar 20608). 72. A. meja sp. n. (ZFMK, Ar 20610). 73. A. tolire sp. n. (ZFMK, Ar 20613). 74. A. tinoor sp. n. (ZFMK, Ar 20616). Scale lines: 0.3.

FIGURES 81–89. Arnapa spp., epigyna, ventral views, and cleared female genitalia, ventral and dorsal views. 81–83. A. meja sp. n. (ZFMK, Ar 20610). 84–86. A. tolire sp. n. (ZFMK, Ar 20613). 87–89. A. tinoor sp. n. (ZFMK, Ar 20616). Scale lines: 0.5.

FIGURES 90–97. Arnapa tolire sp. n. (90–94, ZFMK, Ar 20613) and A. tinoor sp. n. (95–97, ZFMK, Ar 20615–16). 90–91. Female prosoma, frontal views. 92. Left female palp and chelicerae; note absence of stridulatory files. 93. Female palpal tarsal organ. 94–95. Epigyna, ventral views. 96–97. Female and male spinnerets. ALS, anterior lateral spinneret; ch, chelicera; PMS, posterior median spinneret; pto, palpal tarsal organ. Scale lines: 10 µm (93, 96–97), 100 µm (90–92, 94–95).