On the Bennelongia barangaroo lineage (Crustacea, Ostracoda) in Western Australia, with the description of seven new species

Abstract

The ostracod genus Bennelongia De Deckker & McKenzie, 1981 is endemic to Australia and New Zealand. Extensive sampling in Western Australia (WA) revealed a high specific and largely undescribed diversity. Here, we describe seven new species belonging to the B. barangaroo lineage: B. timmsi sp. nov., B. gnamma sp. nov., B. hirsuta sp. nov., B. ivanae sp. nov., B. mcraeae sp. nov., B. scanloni sp. nov. and B. calei sp. nov., and confirm the presence of an additional species, B. dedeckkeri, in WA. For five of these eight species, we could construct molecular phylogenies and parsimonious networks based on COI sequences. We also tested for cryptic diversity and specific status of clusters with a statistical method based on the evolutionary genetic species concept, namely Birky’s 4 theta rule. The analyses support the existence of these five species and a further three cryptic species in the WA B. barangaroo lineage. The molecular evidence was particularly relevant because most species described herein have very similar morphologies and can be distinguished from each other only by the shape, size and position of the antero-ventral lapel on the right valve, and, in sexual populations, by the small differences in shape of the hemipenes and the prehensile palps in males. Four species of the WA B. barangaroo lineage occur in small temporary rock pools (gnammas) on rocky outcrops. The other four species are mainly found in soft bottomed seasonal water bodies. One of the latter species, B. scanloni sp. nov., occurs in both claypans and deeper rock pools (pit gnammas). All species, except for B. dedeckkeri, originally described from Queensland, have quite clearly delimited distributions in WA. With the seven new species described here, the genus Bennelongia now comprises 25 nominal species but several more await formal description.

Improved protocols to accelerate the assembly of DNA barcode reference libraries for freshwater zooplankton

“…Low barcode success rates have also been reported for cladocerans and rotifers, and most barcode studies on these groups are taxonomically limited in scope (Elías-Gutiérrez, Martínez-Jerónimo, et al, 2008;Hwang, Dahms, Park, & Lee, 2013;Jeffery, Elías-Gutiérrez, & Adamowicz, 2011;Proios et al, 2014). Although DNA barcodes successfully discriminate other taxa of freshwater zooplankton such as ostracods (Cohuo-Durán, Elías-Gutiérrez, & Karanovic, 2013;Martens, Halse, & Schoen, 2015), no broad barcoding studies have been undertaken.…”

On the Bennelongia nimala and B. triangulata lineages (Crustacea, Ostracoda) in Western Australia, with the description of six new species

“…Males with different valve shape have slightly different morphologies in the rpp, but as this could be part of a normal range of variability, its occurrence should be checked on longer series of dissections. Bennelongia timmsi Martens et al, 2013 also showed significant variability in the shape of the Rpp .…”

“…Most species also with very pronounced anterior lV/rV overlap, most pronounced of all lineages in this genus. Some species with an inner 'eyelet' in the anterior part of the RV, close to the lapel, just as in the species of the B. barangaroo lineage (see Martens et al 2013), to which this lineage is most closely related. Fig …”

“…nov. and B. muggon sp. nov.) have an eyelet in the anteroventral part of the rV, much as in the B. barangaroo lineage (see Martens et al 2013), indicating that these lineages are more closely related to one another than the valve morphology might indicate at first glance. Species of the B. barangaroo lineage have valves that are much smoother and only weakly pitted, although they can in some species be quite hirsute.…”

Redescriptions of six species of Ilyodromus Sars, 1894 (Crustacea, Ostracoda, Cyprididae) from New Zealand and Eastern Australia

“…Nevertheless, the development of a chaetotaxal model (Broodbakker & Danielopol 1982;Martens 1987;Meisch 2000), the advancement of dissection techniques, higher magnification compound microscopes and scanning electron microscopy have since enabled the illustration of a larger suite of taxonomic characters (e.g. Halse & McRae 2004;Savatenalinton & Martens 2009), while the use of genetic species identification methods in new species descriptions (Martens et al 2012(Martens et al , 2013Shearn et al 2012) further adds to the available set of taxonomic characters. The resulting disparity of character sets between old and new descriptions has often made comparison of closely related species difficult during species diagnosis.…”