Implications of a cheliceral axial duplication in Tetragnatha versicolor (Araneae: Tetragnathidae) for arachnid deuterocerebral appendage development.

The homology of the arachnid chelicera with respect to other head appendages in Panarthropoda has long been debated. Gene expression data and the re-interpretation of early transitional fossils have supported the homology of the deutocerebrum and its associated appendages, implying a homology between primary antennae (mandibulates), chelicerae (euchelicerates), and chelifores (sea spiders). Nevertheless, comparatively little is known about the mechanistic basis of proximo-distal (PD) axis induction in chelicerates, much less the basis for cheliceral fate specification. Here, we describe a new cheliceral teratology in the spider Tetragnatha versicolor Walckenaer, 1841, which consists on a duplication of the PD axis of the left chelicera associated with a terminal secondary schistomely on the fang of the lower axis. This duplication offers clues as to potential shared mechanisms of PD axis formation in the chelicera. We review the state of knowledge on PD axis induction mechanisms in arthropods and identify elements of gene regulatory networks that are key for future functional experiments of appendage development in non-insect model systems. Such investigations would allow a better understanding of PD axis induction of modified and poorly studied arthropod limbs (e.g., chelicerae, chelifores, and ovigers).

The artoriine wolf spiders of Australia: the new genus Kochosa and a key to genera (Araneae: Lycosidae).

A key to the six Australian genera of the wolf spider (Lycosidae Sundevall, 1833) subfamily Artoriinae Framenau, 2007 is provided, now including Artoria Thorell, 1877, Artoriopsis Framenau, 2007, Diahogna Roewer, 1960, Kangarosa Framenau, 2010, Kochosa gen. nov. and Tetralycosa Roewer, 1960. Kochosa gen. nov. is described to include 16 species: K. australia sp. nov. (type species; from New South Wales, Queensland, South Australia, Victoria, Western Australia), K. aero sp. nov. (Western Australia), K. asterix sp. nov. (New South Wales, Queensland, Tasmania and Victoria), K. confusa sp. nov. (Queensland), K. erratum sp. nov. (Queensland), K. fleurae sp. nov. (Victoria), K. mendum sp. nov. (Australian Capital Territory, New South Wales, Queensland), K. nigra sp. nov. (Queensland), K. obelix sp. nov. (Western Australia), K. queenslandica sp. nov. (Queensland), K. sharae sp. nov. (South Australia), K. tanakai sp. nov. (New South Wales, Queensland), K. tasmaniensis sp. nov. (Tasmania), K. timwintoni sp. nov. (Western Australia), K. tongiorgii sp. nov., (Queensland), and K. westralia sp. nov. (Western Australia). Kochosa gen. nov. differs distinctly from all other genera within the Artoriinae by somatic and genitalic morphology. Most conspicuous is a distinct off-white or yellowish-white cardiac mark on an otherwise generally uniformly dark abdomen. The cardiac mark is rendered by thick black setae, which are particularly dense posteriorly. The tegular apophysis of the male pedipalp is heavily reduced, generally forming a semi-transparent small lobe. In turn, the embolic division is often complex with a variety of apophyses. Kochosa gen. nov. generally inhabit mesic habitats such as temperate and tropical shrubs and forests along the eastern and south-eastern coast and in the south-western parts of Australia.

Two new species in the orb-weaving spider genus Larinia Simon, 1874 (Araneae, Araneidae) from Western Australia.

Two new species in the orb-weaving spider genus Larinia Simon, 1874 are described, L. sexta n. sp. and L. tumulus n. sp. This elevates the Australian number of described species in the genus to seven. With the exception of two females of L. sexta n. sp. recorded from mainland Western Australia, both species have so far exclusively been found on Barrow Island, 50 km off the north-western Western Australian coast where a third species, L. montagui Hogg, 1914, also occurs. Both new species appear to favour spinifex (Triodia spp.) grassland, but specimen numbers in collections are too low to accurately characterize life history patterns and habitat preferences.

The scorpion-tailed orb-weaving spiders (Araneae, Araneidae, Arachnura) in Australia and New Zealand.

The scorpion-tailed orb-weaving spiders in the genus Arachnura Vinson, 1863 (Araneidae Clerck, 1757) are revised for Australia and New Zealand. Arachnura higginsii (L. Koch, 1872) only occurs in Australia and A. feredayi (L. Koch, 1872) only in New Zealand. A single female collected in south-eastern Queensland (Australia) is here tentatively identified as A. melanura Simon, 1867, but it is doubtful that this species has established in Australia. Two juveniles from northern Queensland do not conform to the diagnoses of any of the above species and are illustrated pending a more thorough revision of the genus in South-East Asia and the Pacific region. An unidentified female from Westport (New Zealand) does not conform to the diagnoses of A. feredayi and A. higginsii, but is not described due to its poor preservation status. Arachnura caudatella Roewer, 1942 (replacement name for Epeira caudata Bradley, 1876), originally described from Hall Sound (Papua New Guinea) and repeatedly catalogued for Australia, is considered a nomen dubium.