Bennelongia mcraeae, Martens & Halse & Schön, 2013

Martens, Koen, Halse, Stuart & Schön, Isa, 2013, On the Bennelongia barangaroo lineage (Crustacea, Ostracoda) in Western Australia, with the description of seven new species, European Journal of Taxonomy 66, pp. 1-59 : 35-38

Bennelongia mcraeae sp. nov.

Figs 16-17

urn:lsid:zoobank.org:act:DFD1A720-E602-46CC-AABF-C6EDD63CD70E

Diagnosis

Valves ( Fig. 16 A-B, E-F) high and rounded, with greatest height situated on or close to the middle, dorsal margins almost evenly rounded; ventral margin weakly sinuous. LV ( Fig. 16A, E ) with anteroventral il large, reaching over half of the anterior margin; dorsal il descending along ca. 4/5 of anterior margin, both lists thus clearly overlapping. RV ( Fig. 16B, F ) with antero-ventral lapel fairly ventrally inserted, large and pronounced, with rounded, weakly crenulated margin ( Fig. 16D , I-L). Carapace in lateral view ( Fig. 16 C- D) pitted, especially along anterior and posterior margins, and set with few setae.

Hemipenes ( Fig. 17A, F ) largely symmetrical, ls with broad base, ventrally bluntly beak-shaped, only protruding significantly beyond ventral tip of ms. Right prehensile palp ( Fig. 17C, E ) with distal segment stout, but of somewhat variable shape, either strongly subquadrate or with rounded dorsal and anterior

margins. Left prehensile palp ( Fig. 17B, D ) with distal segment long and slender, reaching beyond ventro-apical margin of proximal segment with at least half of its length.

Etymology

The species is named in honour of Jane McRae (Perth, WA) in acknowledgement of her vast knowledge of the taxonomy and morphology of many invertebrate groups of Western Australia. She also collected the type material of the present species and has unrelentingly provided technical help towards the present revision of Bennelongia since 2006.

Measurements (all measurements in µm – see Table 1 for measurements of all specimens illustrated with SEM)

Holotype ♂ ( WAMC52286 ): RV: L = 1480, H = 878. LV: L = 1560, H = 896.

Allotype ♀ ( WAMC52287 ): RV: L = 1608, H = 1002. LV: L = 1663, H = 1033.

Type locality

Arro Lake, ca. 11 km NW of Eneabba, WA. Approximate coordinates: 29º44’11” S, 115º09’58” E (WGS 84). All specimens collected by J. McRae & A. Pinder (voucher OST14B; locality code SPS182) on 23 Sep. 1999 with a sweep net. Arro Lake is an open lake with a Melaleuca / Casuarina fringe. Water chemistry at the time of collecting: Salinity = 0.15 g /l, pH = 7.32. Nutrient levels were fairly high: total N = 1700 µg /l; total P = 220 µg /l. The milky-white colour of the water equates to a high level of turbidity (2200 NTU).

Type material

Holotype

♂ ( WAMC52286 ), with soft parts dissected in a sealed slide and valves stored dry in a micropalaeontological slide.

Allotype

♀ ( WAMC52287 ), with soft parts dissected in a sealed slide, and valves stored dry in a micropalaeontological slide.

Paratypes

Two ♂♂ (dissection: OC.3328; valves: WAMC 52288) and one ♀ carapace ( WAMC 52289). Three females in bulk in EtOH ( WAMC 52290).

Differential diagnosis

The species is characterised especially by the large and stout lapel on the RV but also by the large anteroventral il on the LV.

Ecology and distribution

Lake Arro (ca. 300 km N of Perth) is a large flat-bottomed body of water with episodic inflow that holds water for about 4-24 months after inflow. The lake has a clay base and sediment-driven turbidity. This species is known only from the type locality. From the same sample as the one that yielded B. macraeae sp. nov., Timms (2002) described a new species of Anostraca , Branchinella complexidigitata Timms, 2002 .

Figures

Fig. 16. Bennelongia mcraeae sp. nov., type specimens from type locality (Arro Lake, OSTR014). A. ♀ allotype, LVi (WAMC52287). B. ♀ allotype, RVi (idem). C. ♀ paratype, CpRL (WAMC52289). D. ♀ paratype, CpRL, detail anterior (idem). E. ♂ holotype, LVi (WAMC52286). F. ♂ holotype, RVi (Idem). G. ♂ holotype, LVe (idem). H. ♂ holotype, RVe (idem). I. ♂ holotype, RVe, detail anterior (idem). J. ♂ holotype, RVi, detail anterior (idem). K. ♂ holotype, RVi, detail anterior, tilted (idem). L. ♀ allotype, RVi, detail anterior, tilted (WAMC52287). Scales = 1 mm unless otherwise indicated.

Fig. 17. Bennelongia mcraeae sp. nov., type males from type locality (Arro Lake, OSTR014B). — A-C. Holotype ♂ (WAMC52286). A. Hemipenis. B. Left prehensile palp. C. Right prehensile palp. — D-F. Paratype ♂ (OC.3328). D. Left prehensile palp. E. Right prehensile palp. F. Hemipenis. Scale: A-F = 92 µm.