Bennelongia coondinerensis, Martens & Schön, 2012

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 : 24-27

Bennelongia coondinerensis sp. nov.

( Figs 12 , 13 , 14A, B )

Etymology

The species is named after its type locality, Coondiner Pool, Pilbara.

Diagnosis

Cp with pronounced anterior rostrum, and weaker posterior rostrum. LV with pronounced anteroventral beak and rounded dorsal margin. Lapel on RV tear-shaped, dorsally sloping towards valve margin. Hemipenis with MS with straight margin, ventrally widely produced as a rounded lobe; ls in one hemipene rounded, and distally bluntly pointed, in second hemipenis distally with thumb-like process; tips of ls and ms well-separated, ls extending clearly beyond ms. Rpp with distal segment triangular, rather broad. Lpp with proximal segment bearing rectangular apical outgrowth; distal segment sickleshaped, tapering and rather elongated.

Measurements (all measurements in µm)

Male: RV: L = 1640, H = 971. LV: L = 1690, H = 911. Cp: L = 1690-1710; W = 911-913.

Female: RV: L = 1750, H = 1040. LV: L = 1860, H = 1120. Cp: L = 1810-1890; W = 1020-1080.

Type locality

Coondiner Pool, Pilbara, WA (sample KIES14); approximate coordinates: 22º 43’26”S 119º 39’ 23”E. All material used for the present description collected on 24 Apr. 2006 by the authors.

Type material

Holotype

Male ( WAM.C49389 ), with soft parts dissected in a sealed slide and valves stored dry in a micropalaeontological slide.

Allotype

Female ( WAM.C49390), with soft parts dissected in a sealed slide and valves stored dry in a micropalaeontological slide.

Paratypes

One male dissected and stored as the holotype (OC.3315); three male carapaces ( WAM.C49391A, WAM.C49392), two female carapaces ( WAM.C49391B-C). 2 RV +1LV of a female (OC.3317A-C).

Several in toto specimens in EtOH ( WAM.C49393).

Other material investigated

Ethel Creek Clay pan, Pilbara, approximate coordinates: 22º 49’ 32”S 120º 15’ 32”E. Collected by the authors on 24 Apr. 2006.

Differential diagnosis

The species belongs to the B. australis group because of the generally large size (L> 1500 µm), the presence of a lapel on the RV and of a strong anterior rostrum in dorsal view. It can be distinguished from the other species in this lineage by the rounded dorsal margin of the LV, the tear-shaped lapel, the broad second segment of the Rpp, the fact that tips of ls and ms of the hemipenes are well-separated from each other and that ls extends well beyond the ms.

The shape of the lapel somewhat resembles that of the second species redescribed by De Deckker (1981a) as B. australis (from a pool close to Cunderdin), yet these latter specimens have much more highly arched valves, while also the edge of the beak in the LV is less pointed than in B. coondinerensis sp. nov.

Additional description

Valves in lateral view with rounded dorsal margin ( Figure 12 A-D), LV overlapping RV on all sides ( Figure 12K, L ), greatest height anterior to the middle; in dorsal and ventral views ( Figure 12 E-H) with greatest width in the middle of the carapace; anterior rostrum well-developed, posterior side weakly pointed, LV dorsally ridge-like; external surface weakly pitted and set with setae of intermediate length.

LV in inner view ( Figure 12A, C ) with rounded dorsal margin, greatest height situated in the middle; antero-ventral beak-like expansion rather large; posterior part of ventral margin markedly sloping in dorsal direction.

RV ( Figure 12D ) in inner view with greatest height situated in front of the middle, dorsal margin almost straight for about the middle third; posterior selvage clearly inwardly displaced in the posterior half of the valve, posterior inner list merging with posterior selvage at about halfway the length of the latter; lapel tear-shaped ( Figure 12I, J ), dorsally sloping towards the valve margin, ventrally abruptly curving towards it; antero-ventral inner list running to about halfway the lapel; selvage at height of lapel expanded and slightly striate.

Most appendages as typical of the genus and without special features.

Rpp ( Figure 13A ) with first segment c. 1.5 times as long as wide, subapically with one long but slender, and one short sensory organ; second palp segment triangular, rather broad, with almost straight distal margin; apically with one small sensory organ.

Lpp ( Figure 13B ) with first segment elongated, more than twice as long as central width, subapically with one stout sensory organ, apically with a rectangular outgrowth, bearing one small sensory organ; second palp segment sickle-shaped and relatively elongated (L> ½ L of first segment).

T2 ( Figure 13C ) a hirsute walking leg, with seta d1> seta d2. Hemipenes ( Figure 14A, B ) with tips of ls and ms well separated from one another, ls reaching well beyond tip of ms, distal part of ms produced into an elongated lobe; distal part of ls bluntly pointed with distal margin rounded in one hemipenis, ls almost rectangular with distal thumb-like process in the other.

Ecology and distribution

Bennelongia coondinerensis sp. nov. has thus far been found in two localities in the Pilbara region. Both clay pans had turbid waters (through suspended clay), with a thin layer of planktonic algae in the top few centimetres of turbid water. This ostracod species has been recorded in water with conductivity 104-197 µS cm-1 and pH 7.7-10.2. This high pH is almost certainly owing to photosynthetic activity of the mentioned algae.

Figures

Fig. 12. Bennelongia coondinerensis sp. nov., all from Coondiner Pool (Type locality). A. LVi (allotype ♀, WAM.C49390). B. RVi (♀, Idem). C. LVi (holotype ♂, WAM.C49389). D. RVi (♂, Idem). E. Cp dorsal (♀, WAM.C49391C). F. Cp ventral (♀, WAM.C49391B). G. Cp ventral (♂, WAM.C49392B). H. Cp dorsal (♂, WAM.C49392A). I. RVi (detail anteriorly, holotype ♂, WAM.C49389). J. RVi (detail anteriorly, allotype ♀, WAM.C49390). K. CpRe (♂, WAM.C49391A). L. CpRe (♀, WAM.C49391C). Scales: A-H, K-L = 1000 µm; J = 200 µm; I = 100 µm.

Fig. 13. Bennelongia coondinerensis sp. nov. ♂. A. T1, showing right prehensile palp (holotype ♂, WAM.C49389). B. Left prehensile palp (Idem). C. T2 (OC.3315). Scales: C = 232 µm; A,B = 92 µm.

Fig. 14. A-B. Bennelongia coondinerensis sp. nov. (holotype ♂, WAM.C49389); C-F. Bennelongia gwelupensis sp. nov. (♂, WAM.C49397). A. Hemipenis outline. B. Other hemipenis, showing inner anatomy. C. Right prehensile palp. D. Hemipenis outline. E. Left prehensile palp. F. Outline of second hemipenis, same individual. Scales: D, F = 232 µm; A, B, C, E = 92 µm.