Bennelongia australis (Brady, 1886)

Martens, Koen, Halse, Stuart & Schön, Isa, 2012, Nine new species of Bennelongia De Deckker & McKenzie, 1981 (Crustacea, Ostracoda) from Western Australia, with the description of a new subfamily, European Journal of Taxonomy 8, pp. 1-56 : 23-24

Bennelongia australis - lineage

Remarks

Brady (1886) described Chlamydotheca australis based on empty valves collected by Prof R. Tate from Penola (South Australia). The description was incomplete and, as pointed out by De Deckker (1981a), most likely also erroneous: although the LV ( Brady 1886, plate 9 fig. 7) is undoubtedly of a species of Bennelongia , the RV is not. De Deckker (loc.cit.) investigated the type material of Chlamydotheca australis in the British Musuem (presently the Natural History Museum, London) and found that the slide contained the illustrated Bennelongia LV as well as a second LV, most likely belonging to a species of Heterocypris . It is likely that this is the valve illustrated by Brady (1886, plate 9 fig. 8). As it is the RV that shows most specific features of Bennelongia species, the true identity of Bennelongia australis will be impossible to establish based on the type material only. New material from Penola will be necessary and topotypes must be established to determine what species is the true B. australis . Below, we describe 5 sibling species in this lineage, which can be identified based on shape of the valves, form of the lapel on the RV, shape of the hemipenis and of the prehensile palps. The identity of four of these species was confirmed by molecular screening (see above).

De Deckker (1981a) extensively redescribed what he thought to be B. australis , based on material from Western Australia (mainly from pools near Leonora and Cunderdin). Based on the illustrated lapels, it is clear that this redescription is based on at least two different species within the B. australis lineage, neither of which are present in our collections. Given the regional specificity of the species within this lineage, it is unlikely that the true B. australis , described from South Australia is amongst the species used by De Deckker (1981a).

Davies & Christidis (1997) also illustrated a specimen of what they labelled B. australis , collected from lakes in and around Perth.We have collected material from two of the same lakes and describe this species below as B. gwelupensis sp. nov. The species figured by Davies & Christidis (1997) as Bennelongia sp. was described above as B. cygnus sp. nov. Karanovic (2008) illustrated specimens from Pilbara as B. australis s.l. These specimens belong to B. strellyensis sp. nov. in the B. pinpi lineage (see below).

The B. australis lineage is characterized by relatively large carapaces, LV with intermediately sized beaks and RV with lapel. Most species described here also have rounded dorsal margins and have pronounced anterior (and sometimes posterior) rostrum in dorsal view.