Wednesday, April 27, 2016

[Invertebrate • 2016] Hantu gen. nov. • A New Genus of Ground and Litter-Dwelling Pholcine Spiders (Araneae, Pholcidae) from Sarawak




Abstract

Two small, ground and litter-dwelling pholcid species from northern Borneo are described as representatives of a new genus, Hantu gen. nov.: H. kapit gen. et sp. nov. and H. niah gen. et sp. nov. Previous cladistic analyses suggested a closer relationship with the genera Savarna Huber, 2005 and Khorata Huber, 2005 (mainland Southeast Asia) than with the geographically closer genus Aetana Huber, 2005 (Borneo and Philippines to Fiji). Since the two species do not share any of the synapomorphies of Khorata and Savarna while having several synapomorphies on their own (ventral apophysis on male palpal coxa; male palpal trochanter apophysis with small teeth or scales; spines on male femora 1; high density of vertical hairs on male femora; presence of scape on epigynum), they are here proposed as representing a new genus.

Keywords. Borneo, Sarawak, endemism, taxonomy, Pholcidae. 




Class Arachnida Cuvier, 1812
Order Araneae Clerck, 1757
Family Pholcidae C.L. Koch, 1851

Hantu gen. nov.
urn:lsid:zoobank.org:act:9DBCF7B6-8A03-4346-BFA7-9DE99CD065D7

Type species: Hantu kapit gen. et sp. nov.

Diagnosis: Small, six-eyed, dark, ground and litter-dwelling pholcids with dark (usually black) sternum, with thoracic furrow extending over entire length of carapace, and without epiandrous spigots. Distinguished from putatively closest known relatives (Khorata, Savarna) by ventral apophysis on male palpal coxa (arrows in Figs 9, 19, 27), by scales or teeth on male palpal trochanter (Fig. 16), by spines on male femora 1 (~10–25 in single ventral row), by short vertical hairs in high density on male femora (in two dorsal rows), and by scape on female external genitalia (Figs 40–45); from Savarna also by presence of distal cheliceral apophyses (Figs 11, 28) and by male palpal trochanter apophysis not fused to femur (Figs 9, 27); from Khorata also by absence of sclerotized ledges laterally on male chelicerae (Figs 11, 28) and by absence of retrolateral process on male palpal femur (Figs 9, 27).

Etymology: Named for the Hantu Rimba, deep-forest ghosts in traditional Malaysian mythology. Gender masculine.

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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.


Bernhard A. Huber. 2016. A New Genus of Ground and Litter-Dwelling Pholcine Spiders from Sarawak (Araneae, Pholcidae). European Journal of Taxonomy. 186: 1–15. DOI: 10.5852/ejt.2016.186

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