Arnapa arfak 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 : 16-19

Arnapa arfak Huber sp. n.

Figs 39–40 , 45–49 , 70 , 75–77

Gen.n. Ind96: Eberle et al. 2018 (molecular data); Huber et al. 2018: fig. 2.

Type material. INDONESIA: ♂ holotype, ZFMK (Ar 20604), West Papua, Arfak Mountains, forest above Mokwam (1.112°S, 133.911°E), 1600 m a.s.l., near ground, 5–6.xi.2009 (S. Sutono) .

Other material examined. INDONESIA: 2♂ 7♀ 2 juvs, ZFMK (Ar 20605), and 1♀ 4 juvs in pure ethanol,

ZFMK (Ind196), same data as holotype. 3♂ 1♀, ZFMK (Ar 20606), West Papua, Arfak Mountains, forest along stream above Syobri village (1.114°S, 133.906°E), 1680 m a.s.l., among rocks, 7.xi.2009 (S. Sutono).

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

Diagnosis. Easily distinguished from known congeners by wide procursus (especially in dorsal view; Fig. 47 ) and by roundish epigynum with strong transversal ridges anteriorly ( Fig. 75 ); from most congeners also by armature of male chelicerae ( Fig. 48 ; two distinctive distal apophyses on each side directed towards median; similar only in A. manokwari ); also by bulbal process ( Fig. 49 ; with wide flat curved sclerite) and by distal elements of procursus ( Fig. 47 ).

Description. Male (holotype). MEASUREMENTS. Total length 2.2, carapace width 1.05. Distance PME-PME 110 µm; diameter PME 110 µm; distance PME-ALE 120 µm; distance AME-AME 20 µm, diameter AME 50 µm. Leg 1: 28.2 (6.7 + 0.4 + 7.0 + 11.8 + 2.3), tibia 2: 3.9, tibia 3: 2.8, tibia 4: 4.0; tibia 1 L/d: 78.

COLOR (in ethanol). Carapace ochre-orange with wide dark brown bands laterally and medially, including posterior part of ocular area; clypeus with pair of dark bands between eye triads and rim; sternum light brown to orange; legs brown, with indistinct darker rings on femora (distally) and tibiae (proximally). Abdomen gray, dorsally densely covered with dark marks, ventrally with slightly darker mark in gonopore area, dark median band behind gonopore, light brown area and pair of large dark ventro-lateral marks in front of spinnerets.

BODY. Habitus as in Fig. 39 . Ocular area elevated, thoracic furrow present; clypeus unmodified, only strongly protruding towards rim. Sternum wider than long (0.70/0.46), unmodified.

CHELICERAE. As in Fig. 48 , with several sclerotized cones in distinctive arrangement, no modified hairs, with stridulatory ridges.

PALPS. As in Figs 45–46 ; coxa unmodified, trochanter with short ventral apophysis, femur strongly widened, with large rounded retrolateral process proximally, with stridulatory pick (modified hair) proximally, patella ventrally reduced (not closed), tarsus small, procursus with large flat dorsal apophysis proximally, with ventral groove (rather than distinct ventral pocket), distally with sclerotized and membranous elements ( Fig. 47 ); genital bulb large, with complex process ( Fig. 49 ).

LEGS. Without spines, few vertical hairs; with weakly curved hairs on all tibiae and metatarsi (especially anterior legs); retrolateral trichobothrium of tibia 1 at 4.5%; prolateral trichobothrium present on all tibiae; tarsus 1 with>30 pseudosegments, distally distinct.

Male (variation). Number of sclerotized cones on chelicerae slightly variable but pattern consistent. Tibia 1 in 5 males (incl. holotype): 6.5–7.0 (mean 6.8).

Female. In general similar to male but sternum darker brown. Tibia 1 in 7 females: 4.2–4.9 (mean 4.7). Epigynum anterior plate roundish, with strong transversal ridges in anterior part ( Fig. 75 ); posterior plate large, also with transversal ridges. Internal genitalia with distinctive rounded frontal processes at both sides of ‘valve’ and with internal pockets, with large pore plates and pair of lateral sclerites ( Figs 70 , 76–77 ).

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

Natural history. This species was found in humid forest ( Fig. 336 ) in small domed webs at the basis of trees and in small holes in 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 45–49. Arnapa arfak sp. n. (ZFMK, Ar 20605). 45–46. Left male palp, prolateral and retrolateral views. 47. Left procursus, dorsal view. 48. Male chelicerae, frontal view. 49. Left genital bulb, dorsal view. ba, bulbal apophysis; da, dorsal apophysis; gb, genital bulb; pr, procursus. Scale lines: 0.5.

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 75–80. Arnapa spp., epigyna, ventral views, and cleared female genitalia, ventral and dorsal views; arrows point at internal putative pockets. 75–77. A. arfak sp. n. (ZFMK, Ar 20605). 78–80. A. manokwari sp. n. (ZFMK, Ar 20608). Scale lines: 0.5.

FIGURES 336–341. Selection of collecting sites and habitats. 336. Forest above Mokwam (West Papua), type locality of Arnapa arfak sp. n. and Aetana mokwam sp. n. 337. Tinoor Fall near Tomohon (North Sulawesi), type locality of Arnapa tinoor sp. n. 338. Entrance to Caverna Porco do Mato II (Rio Grande do Norte), type locality of Pinocchio barauna sp. n. 339. Desert between Sur and Kamil (Oman), type locality of Magana velox sp. n. 340. Bromeliad at Reserva Particular do Patrimônio Nacional Serra Bonita (Bahia), type locality of Psilochorus bromelicolus sp. n. (note pair of spiders among leaves). 341. Disturbed forest near Sofifi (Halmahera), type locality of Giloloa sofifi sp. n. and Panjange togutil sp. n.