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Buitinga ifrit Huber & Cazanove, Belisana coblynau Huber & Clark, in Huber, Meng, Clark & Cazanove, 2023. |
Abstract
Daddy long-legs spiders are common inhabitants of tropical and subtropical caves around the globe. Numerous species have evolved troglomorphisms, including the loss of body pigments and eyes. Here we describe the first troglomorphic pholcids from Australia and Réunion. Belisana coblynau Huber & Clark, sp. nov. was extracted from mining boreholes in the arid West Australian Pilbara region. It represents a genus that is widespread in tropical forests of South and Southeast Asia, reaching the tropical north and east of Australia. Belisana coblynau is thus presumably a relict whose epigean ancestor lived in the area before the aridification of Australia starting in the early Cenozoic. Buitinga ifrit Huber & Cazanove, sp. nov. was collected in Grotte de La Tortue on Réunion, one of the oldest lava tubes on the island (~300,000 years). Congeneric species are known from East Africa, and the genus does not seem to have reached Madagascar. Since Pholcidae do not balloon, the now extinct epigean ancestor of Buitinga ifrit probably reached the island by highly accidental means (such as rafts or storms).
Keywords: Lava tube, mining borehole, relict, scrape sample, subterranean, troglomorphism
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Buitinga ifrit Huber & Cazanove, sp. nov., male holotype and female paratype, ZFMK (Ar 24187–88) A male habitus, dorsal view B female abdomen, ventral view (arrow: darker median area) C, D cleared female genitalia, ventral and dorsal views. Abbreviations: ls, dark lateral structure; mp, median posterior process; sp, spinnerets. Scale bars: 0.5 mm (A); 0.2 mm (B); 0.1 mm (C, D). Belisana coblynau Huber & Clark, sp. nov., male holotype and female, WAM T158896–7 A male habitus, lateral view B female abdomen, ventral view C, D cleared female genitalia, ventral and dorsal views. Abbreviations: ep, epigynal pockets; lp, lateral pocket; pp, pore plate; sp, spinnerets. Scale bars: 0.5 mm (A); 0.1 mm (B–D). |
Belisana coblynau Huber & Clark, sp. nov.
Diagnosis: Distinguished from known congeners (and other Pholcinae) by details of procursus (Fig. 2D, E; straight, with simple retrolateral process, bifid prolateral process, and widened membranous tip), genital bulb (Fig. 2A, B; bulbal apophysis short and hooked, embolus straight and pointed at tip), male chelicerae (Fig. 2C; pair of light proximal processes; pair of simple distal frontal apophyses without modified hairs), epigynum (Fig. 1B; protruding, with pair of pockets close together), and female internal genitalia (Figs 1C, D, 2F; pore plates wide apart; distinctive pair of additional internal lateral pockets).
Etymology: The species epithet refers to the mythical gnome-like creatures that are said to haunt mines and quarries (of Wales and beyond); noun in apposition.
Distribution: Known from three neighboring (within 5 km) localities in Western Australia.
Natural history: The spiders were extracted from mining bores in the Hamersley Range using scrape sampling (Fig. 5A–C). This collecting method precludes gaining detailed natural history data. The specimens were collected between ground level and approximately 35 m below ground level. The temperature in these holes at 15 m below ground level was constant at 32–33 °C. For a general characterization of the Pilbara troglofauna, see Discussion.
Buitinga ifrit Huber & Cazanove, sp. nov.
Diagnosis: Distinguished from known congeners (and other Pholcinae) by strong bifid process on male palpal trochanter (Fig. 4B), by details of procursus (Fig. 4E, F; short main branch curved towards dorsal and with deeply bifid tip, large and mostly membranous side branch originating from ventral side of main branch, with complex tip), genital bulb (Fig. 4A; bulbal apophysis slender and weakly curved, with small process at basis, embolus cylindrical), male chelicerae (Fig. 4C, D; pair of light proximal processes; pair of distal frontal apophyses with four modified hairs each), epigynum (Fig. 3B; barely protruding, without pockets, distinctive median posterior process only visible in cleared specimens), and female internal genitalia (Figs 3C, D, 4G; oval pore plates; pair of dark lateral structures).
Etymology: The species epithet refers to a demon in Islamic mythology that is often associated with the underworld; noun in apposition.
Distribution: Known from type locality only.
Natural history: The spiders were collected deep within the Grotte de la Tortue lava tube (Fig. 5D, E). Some of the specimens were collected in the Salle du Muséum, a section that is about 150 m from the cave entrance (see topographic map in Hoch et al. 2003). They were found among rocks on the ground. For the other specimens, cave section and microhabitat are unknown. For a general characterization of the caves and cave fauna of Réunion, see Discussion.
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| Epigean and hypogean habitats and collecting method A Hamersley Range in Western Australia; the area of the sampled boreholes B weighted net (arrow) above a borehole C weighted net used for scrape sampling D main entrance of the Grotte de La Tortue (photo T. Percheron, 2015) E gallery of the lost goat in Caverne de La Tortue (photo T. Percheron, 2022). |
Bernhard A. Huber, Guanliang Meng, Huon L. Clark and Grégory Cazanove. 2023. First blind Daddy long-legs Spiders from Australia and Réunion (Araneae, Pholcidae). Subterranean Biology. 46: 1-19. DOI: 10.3897/subtbiol.46.105798
