Hantu niah, Huber, 2016

Bernhard A. Huber, 2016, A new genus of ground and litter-dwelling pholcine spiders from Sarawak (Araneae, Pholcidae), European Journal of Taxonomy 186, pp. 1-15 : 9-13

Hantu niah gen. et sp. nov.

urn:lsid:zoobank.org:act:0C378095-994C-427A-8989-E119A644A7EC

Figs 3–6 , 26–39 , 43–45

Gen.n. Bor20 – Huber et al. 2015a: 73–74.

Diagnosis

Easily distinguished from H. kapit gen. et sp. nov. by absence of horns in male ocular area ( Fig. 31 ), by highly distinctive male palp ( Figs 26–27 ; square-shaped trochanter apophysis; dorsal process on procursus), by strong distal apophyses on male chelicerae ( Fig. 28 ), and by scape on epigynum ( Figs 29 , 43 ) more sclerotized and without Fne transversal folds. From other putatively close relatives in the genera Khorata and Savarna by male procursus shape (dorsal process) and epigynal scape.

Etymology

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

Type material

MALAYSIA-BORNEO: holotype, Ƌ, Sarawak, Niah Cave N.P. , forest near cave, 3.814° N, 113.771° E, 40 m a.s.l., 28 Jul. 2014 (B.A. Huber), ZFMK ( Ar 15071 ) .

Other material examined

MALAYSIA-BORNEO, Sarawak: 10 ƋƋ, 15 ♀♀, 1 juv., same data as holotype, ZFMK ( Ar 15072–73 ; 9 ƋƋ, 14 ♀♀) and SMK (1 Ƌ, 1 ♀) ; 4 ♀♀, same data, in pure ethanol, ZFMK ( Bor 226 ) ; 2 ♀♀, Niah Cave N.P. , forest along main trail, 3.814– 3.821° N, 113.763– 113.771° E, 20–40 m a.s.l., 27 Jul. 2014 (B.A. Huber, S.B. Huber), ZFMK ( Ar 15074 ) ; 1 ♀, 1 juv., same data, in pure ethanol, ZFMK ( Bor 177 ) .

Description

Male (holotype)

MEASUREMENTS. Total body length 2.3, carapace width 1.0. Leg 1: 20.5 (5.0 + 0.4 + 5.1 + 7.7 + 2.3), tibia 2: 3.0, tibia 3: 2.2, tibia 4: 2.9; tibia 1 L/d: 58. Distance PME-PME 420 µm, diameter PME 90 µm, distance PME-ALE 25 µm, no AME.

COLOR. Carapace light ochre with narrow lateral dark margins and large median dark mark including ocular area. Clypeus not darkened. Sternum dark brown. Legs ochre to light brown, without dark rings. Abdomen grey with large dorsal and lateral marks; ventrally with three large dark marks (in genital area, at spinnerets, and in-between).

BODY. Habitus as in Figs 3–4 ; ocular area slightly raised, each triad on short stalk directed toward lateral ( Fig. 31 ); carapace with shallow but distinct thoracic furrow; clypeus unmodiFed; sternum wider than long (0.65/0.55), unmodiFed. Chelicerae as in Fig. 28 , with pair of proximal lateral apophyses and pair of strong distal apophyses curved toward median line; without modiFed hairs.

PALPS. As in Figs 26–27 , coxa with sclerotized protruding rim ventro-distally; trochanter with short but very large, square-shaped ventral apophysis with very small teeth distally; femur very large, without processes; patella unusually long; tibia long and slender. Procursus very long; with distinctive dorsal process and complex tip. Bulb oval, with simple weakly sclerotized embolus.

LEGS. With single ventral row of ~10 spines on femora 1; without curved hairs; with short vertical hairs in two dorsal rows on all femora and tibiae; retrolateral trichobothrium on tibia 1 at 7.5%; prolateral trichobothrium absent on tibia 1, present on other tibiae. Tarsus 1 pseudosegments indistinct, only distally ~20 visible in dissecting microscope.

Male (variation)

Tibia 1 in 8 other males: 4.8–5.3 (mean 5.0). Margins of carapace sometimes not dark; dorsal pattern on abdomen sometimes indistinct. Number and thickness of spines on femora variable, from few barely thicker hairs (small males) to ~20 distinct spines (large males).

Female

In general similar to male ( Figs 5–6 ); eye triads closer together (distance PME-PME 220 µm), not on stalks ( Fig. 34 ); no spines on femora; fewer vertical hairs on femora and tibiae (but especially on tibiae also with higher than usual density). Tibia 1 in 16 females: 4.3–4.7 (mean 4.5). Entire epigynal area protruding, posteriorly sclerotized with distinctive scape ( Figs 29 , 43, 44 ); internal genitalia as in Figs 30 and 45 .

Natural history

The spiders were found close to the ground in small domed webs among and under rocks, under dead leaves, and in little cavities. They were extremely efFcient at escaping through the closed hand, then dropped to the ground and remained motionless, becoming essentially invisible.

Distribution

Known from Niah Cave N.P. only ( Fig. 7 ).

Discussion

Pholcid spiders are widely known for their long-legged representatives, some of which are synanthropic, but a large number of species in a range of genera are actually relatively short-legged ground and litterdwellers. About half of all currently recognized genera either include or consist entirely of such shortlegged species (e.g., Huber 2005a, 2005b, 2011, 2013, 2015; Huber et al. 2005). This suggests multiple convergent shifts among microhabitats; in fact, molecular data support the notion that such shifts have occurred repeatedly in various directions ( Huber et al. 2010; Dimitrov et al. 2013; see also Huber & Dimitrov 2014).

Ground and litter-dwelling pholcids share a similar habitus to a degree that allows reasonable predictions even for museum specimens without microhabitat information. They are small (body size ~ 1–3 mm), relatively short legged (leg 1 length <30 mm), rather dark (brown), and have a globular or oval abdomen. This combination seems to be extremely rare in pholcids living in other microhabitats. The only apparent exception known to me are West and Central African representatives of the genus Anansus Huber, 2007 that were collected by canopy fogging ( Huber 2007).

In Southeast Asia, at least seven pholcid genera other than Hantu gen. nov. include ground and litterdwelling representatives: Aetana Huber, 2005 ; Belisana Thorell, 1898 ; Holocneminus Berland, 1942 ; Pholcus Walckenaer, 1805 ; Savarna Huber, 2005 ; Spermophora Hentz, 1841 ; and wugigarra Huber, 2001.

Figures

Fig. 7. Map of northern Borneo, showing known records of Hantu gen. nov.

Figs 1 – 6. Live specimens. 1 – 2. Hantu kapit gen. et sp. nov., Ƌ and ♀ from Kapit, Sarawak. 3 – 6. Hantu niah gen. et sp. nov., Ƌ and ♀ from Niah, Sarawak.

Figs 26 – 30. Hantu niah gen. et sp. nov., ZFMK Ar 15072 – 73. 26 – 27. Left male palp, prolateral and retrolateral views (arrow points at ventral process on coxa). 28. Male chelicerae, frontal view. 29 – 30. Cleared female genitalia, ventral and dorsal views. Abbreviations: b = genital bulb; e = embolus; p = procursus; tr = trochanter. Scale lines: 0.5 mm (26 – 27, 29 – 30); 0.3 mm (28).

Figs 31 – 39. Hantu niah gen. et sp. nov., ZFMK Ar 15072 – 73. 31. Male prosoma, anterior view. 32. Male gonopore. 33. Male palpal tarsal organ. 34. Female prosoma, frontal view. 35. Tip of right procursus, retrolateral view. 36. Lamellae of left procursus, prolateral view. 37. Epigynum, ventral view. 38. Male ALS. 39. Comb-hairs on male tarsus 4. Scale lines: 8 µm (33); 10 µm (38 – 39); 30 µm (32, 35); 80 µm (36); 200 µm (31, 34, 37).

Figs 40 – 45. Female genitalia; untreated in ventral view, cleared in ventral and dorsal views. 40 – 42. Hantu kapit gen. et sp. nov., ZFMK Ar 15070. 43 – 45. Hantu niah gen. et sp. nov., ZFMK Ar 15073. At varying scales.