Aetana baganihan Huber, 2015

Huber, Bernhard A., Nuñeza, Olga M. & Ung, Charles Leh Moi, 2015, Revision, phylogeny, and microhabitat shifts in the Southeast Asian spider genus Aetana (Araneae, Pholcidae), European Journal of Taxonomy 162, pp. 1-78 : 19-20

Aetana baganihan Huber , sp. nov.

urn:lsid:zoobank.org:act:AA06D026-A4F7-4EA9-9661-77707B2CCFB9

Figs 10–12 , 41–44 , 48–50

Diagnosis

Distinguished from very similar A. libjo Huber , sp. nov. by shapes of bulbal processes (compare Figs 38–39 and 41–42 ), by longer male palpal tibia (2.9–3.2 × longer than wide vs. 2.1–2.4 in A. libjo Huber , sp. nov.), and by longer epigynum and narrower scape (compare Figs 28 and 43 ); from next closest known relative ( A. ocampoi Huber , sp. nov.) by light coloration and several details of male palp and epigynum (especially shapes of bulb and scape). Distinguished from all other congeners by simple procursus and complex bulbal processes and by narrow epigynal scape.

Etymology

Named for the type locality; noun in apposition.

Material examined

Holotype PHILIPPINES: ♂, Mindanao, Davao del Sur Prov., Marilog Distr., Baganihan (7.469° N, 125.250° E), 1210 m a.s.l., primary forest near road, among low vegetation, 15 Feb. 2014 (B.A. Huber), ZFMK ( Ar 13932 ).

Other material

PHILIPPINES: Mindanao, 2 ♂♂, 3 ♀♀, same data as holotype, ZFMK (Ar 13933); 1 juvenile, in pure ethanol, same data as holotype, ZFMK (Phi 258).

Description

Male (holotype)

MEASUREMENTS. Total body length 3.2, carapace width 1.1. Leg 1: 39.3 (9.0 + 0.5 + 9.1 + 17.4 + 3.3), tibia 2: 5.3, tibia 3: 3.6, tibia 4: 5.2; tibia 1 L/d: 77. Distance PME-PME 325 µm, diameter PME 135× 110 µm, distance PME-ALE 20 µm; AME absent.

COLOR. Carapace ochre-yellow with black lateral margins, pair of small dark marks behind ocular area, and dark median mark at posterior rim; ocular area and clypeus pale ochre; sternum bright orange; leg coxae ochre-yellow, other leg segments greenish-ochre (especially femora) to light brown (distal segments); abdomen grey, with distinct dorsal and lateral pattern of black marks and rows of white marks, ventrally with brown band between gonopore and spinnerets (mid-section indistinct).

BODY. Habitus as in Figs 10–12 ; ocular area slightly raised, each triad on low hump directed toward lateral; carapace only anteriorly with very shallow and narrow median furrow; clypeus with indistinct pair of processes near rim, provided with some slightly stronger hairs; sternum wider than long (0.70/0.55), unmodified.

CHELICERAE. As in A. libjo Huber , sp. nov. (cf. Fig. 40 ), with pair of ridge-shaped apophyses distally near median line, without proximal lateral apophyses; without modified hairs; without stridulatory ridges.

PALPS. Proximal segments very similar to A. libjo (cf. Figs 26–27 ), trochanter apophysis and femur apophysis slightly larger, tibia longer (length/width: 0.70/0.24). Genital bulb longer than in A. libjo sp. nov., with all three processes different ( Figs 41–42 ): dorsal process wider proximally; central hinged process with smaller prolateral flap and different tip; ventral hinged process relatively shorter.

LEGS. Without spines, with curved hairs on metatarsi 1–3, with vertical hairs in higher than usual density in one retrolatero-dorsal row on each tibia; retrolateral trichobothrium on tibia 1 at 2%; prolateral trichobothrium absent on tibia 1, present on other tibiae. Tarsus 1 with ~30 pseudosegments, distally distinct.

Male (variation)

Tibia 1 in 2 other males: 8.9, 9.3; ratio of palpal tibia length/width: 2.9, 3.2. Other males without or with indistinct white marks on abdomen.

Female

In general similar to male; eye triads closer together (distance PME-PME 230 µm); clypeus unmodified; tibiae with short vertical hairs in low density; entire median area on carapace darker; clypeus also slightly darker (one female with wide brown median band on carapace extending over ocular area and clypeus); abdomen with or without white marks; tibia 1 in 3 females: 6.7, 6.8, 7.0. Epigynum with large, weakly sclerotized area, posteriorly protruding with short, narrow scape ( Figs 43 , 48–49 ); internal genitalia with large median membranous structure of unknown function ( Fig. 44 ).

Natural history

The spiders were found in strongly domed sheet-webs among high grasses in well-preserved forest. As in A. libjo Huber , sp. nov., males and females were sometimes found close to each other but in separate webs. The locality is shared with the ground-dwelling A. kiukoki Huber , sp. nov.

Distribution

Known from type locality only ( Fig. 3 ).

Figures

Figs 6–12. Live specimens. Aetana ocampoi group. 6–7. A. ocampoi Huber, sp. nov., ♂ from Mt. Isarog, Luzon. 8–9. A. libjo Huber, sp. nov., ♂ and ♀ from Dinagat Island, Mindanao. 10–12. A. baganihan Huber, sp. nov., ♂♂ from Baganighan, Mindanao.

Figs 38–44. — 38–40. Aetana libjo Huber, sp. nov. 38–39. Left genital bulb in prolateral and retrolateral views. 40. Male chelicerae, frontal view. — 41–44. Aetana baganihan Huber, sp. nov. 41–42. Left genital bulb in prolateral and retrolateral views. 43–44. Cleared female genitalia, ventral and dorsal views (asterisk: median membranous structure). Scale lines: 38–39, 41–44 = 0.5 mm; 40 = 0.3 mm.

Figs 45–50. Aetana libjo Huber, sp. nov. (Figs 45–47) and Aetana baganihan Huber, sp. nov. (Figs 48–50), female genitalia; untreated in ventral view, cleared in ventral and dorsal views.

Figs 26–29. Aetana libjo Huber, sp. nov. 26–27. Left male palp, prolateral and retrolateral views (asterisk: retrolateral process of bulb). 28–29. Cleared female genitalia, ventral and dorsal views (asterisk: median membranous structure). b = genital bulb; p = procursus; rt = retrolateral trichobothrium. Scale lines: 26–27 = 0.5 mm; 28–29 = 0.3 mm.

Figs 3–4. Known distributions of the Aetana ocampoi (3) and A. kiukoki (4) groups. The question mark denotes a female specimen assigned tentatively to A. kiukoki.