Cypricercus, Almeida & Ferreira & Higuti & Martens, 2021

Almeida, Nadiny Martins De, Ferreira, Vitor Góis, Higuti, Janet & Martens, Koen, 2021, On two new species of Cypricercus Sars, 1895 (Crustacea, Ostracoda) from Brazil with a discussion on the taxonomy of the genus, Zootaxa 4938 (5), pp. 501-536 : 529

Cypricercus sp. A

( Fig. 18 )

Material examined. A single female from Pombas Lake (sample PAR 879), Paraná River floodplain.

Measurements: See Table 1

Abbreviated diagnosis of female. LV elongated, with dorsal margin almost straight and parallel to ventral margin; anterior margin less broadly rounded than in C. centrurus and in C. alfredo sp. nov. RV also with dorsal margin almost straight and largely parallel to ventral margin, posterior spine almost as long as in C. centrurus and equally centrally placed in the middle of the caudal margin, slightly pointing upwards, but less robust; almost twice as long as in C. alfredo sp. nov. Anterior calcified inner margin in both valves about twice the width of that in C. alfredo sp. nov. LV overlapping RV on all sides ( Fig. 18 ).

Remarks. We are convinced that this is a representative of a new species in the genus, but as we have only a single female, we will refrain from formally describing it here.

Ecology and Distribution. Cypricercus sp. A was found associated with the root systems of E. azurea located in a single lake of the Upper Paraná River floodplain. Water temperature at time of collecting was 26.3°C; pH was basic (8); electrical conductivity was 66.2 µS. cm-1 and dissolved oxygen was 9.4 mg. L- 1 (see Table 2 ).

Figures

FIGURE 18. Cypricercus sp. A. Upper Paraná River floodplain. A–F. Female. A. LVi. B. LVi, detail of anterior part. C. LVi, detail of posterior part. D. RVi. E. RVi, detail of anterior part. F. RVi, detail of posterior part. Scale bars: A, D: 1000 µm. B–C, E: 500 µm. F: 200 µm.