Soil Preference and Burrow Characteristics of Two Theraphosidae Species in Penang Island, Malaysia

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  Soil Preference and Burrow Characteristics of Two Theraphosidae Species in Penang Island, Malaysia Abstract Tarantulas play a crucial role in maintaining ecological balance by regulating insect populations. However, little is known about the soil preferences and burrow structures of tarantulas in Malaysia. This study aims to determine the soil preference as well as the burrow structure of  Coremiocnemis cunciularia  and  Chilobrachys andersoni  from Penang Island. The soil characteristics of the soil samples collected around the burrows of  Coremiocnemis cunciularia  (n = 30) and  Chilobrachys andersoni  (n = 30) were determined using soil texture analysis. The measurements and burrow structures from adults and juveniles of  Coremiocnemis cunciularia  and  Chilobrachys andersoni  were determined. It was revealed that the moisture content and clay percentage in the soil samples around burrows of  Chilobrachys anderso...

Taxonomy and systematics of the Australasian gum nut orb-weaving spider genus Carepalxis (Araneae, Araneidae)

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Taxonomy and systematics of the Australasian gum nut orb-weaving spider genus Carepalxis (Araneae, Araneidae)

Abstract

We revised the orb-weaving spider genus Carepalxis L. Koch, 1872 and tested its monophyly using Maximum Likelihood and Bayesian Inference phylogenetic analyses, comparing our results to a previously published family-level dataset on world-wide Araneidae. We studied the placement of the genus and the classification of the informally termed clade ‘backobourkiines’ using phylogenetic analyses based on two mitochondrial genes, cytochrome c oxidase subunit 1 (COI) and 16S rRNA (16S), and two nuclear genes, 28S rRNA (28S) and 18S rRNA (18S). Approximately 12,000 araneid records (vials) from major Australian and overseas collections were examined during our taxonomic revision. All phylogenetic analyses supported a monophyletic ‘backobourkiines’ clade, but found a polyphyletic Carepalxis, with its Australasian representatives being part of the ‘backobourkiines’ and the Neotropical species being related to the Neotropical Ocrepeira Marx, 1883. Consequently, the genus was revised to include seven endemic Australian species, Carepalxis montifera L. Koch, 1872 (type species), C. bilobata Keyserling, 1886, C. ferreirasousai sp. nov., C. kolla sp. nov., C. megalostylus sp. nov., C. tholos sp. nov. and C. tuberculata Keyserling, 1886 (=C. furcifera (Keyserling, 1886) syn. nov.), in addition to C. beelzebub (van Hasselt, 1873) (=C. suberosa Thorell, 1881 syn. nov. = C. tuberculifera (Thorell, 1881) comb. nov., syn. nov. = C. tricuspidata Chrysanthus, 1961 syn. nov.), which is present in Australia, Indonesia (West Papua) and Papua New Guinea. The following new combinations for Neotropical species previously placed in Carepalxis were proposed: Ocrepeira camelus (Simon, 1895) comb. nov., Ocrepeira gibbosa (O. Pickard-Cambridge, 1889) comb. nov., Ocrepeira perpera (Petrunkevitch, 1911) comb. nov., Ocrepeira quasimodo (Ferreira-Sousa & Motta, 2022) comb. nov., and Ocrepeira topazio (Ferreira-Sousa & Motta, 2022) comb. nov. Within the backobourkiines, Carepalxis can be recognised by the presence of two cephalic humps in females and two enlarged megaspines apically on tibia II of males (both here considered synapomorphies of the genus), an anteriorly elevated abdomen usually with numerous tubercles, humps or sigilla in addition to the humeral humps, an elongated male pedipalp median apophysis bearing a small projection, and a female epigyne with broad lateral lobes, and, whenever present, conspicuous transverse slits instead of baso-lateral flaps.

Castanheira Pedro de S., Dimitrov Dimitar, Baptista Renner L. C., Scharff Nikolaj, Framenau Volker W. (2025) Taxonomy and systematics of the Australasian gum nut orb-weaving spider genus Carepalxis (Araneae, Araneidae). Invertebrate Systematics 39, IS25009.

https://doi.org/10.1071/IS25009