Cyprideis torosa ( Jones, 1850 )

Rausch, Lea & Stoica, Marius, 2019, AN EARLY PLEISTOCENE ANOMALOHALINE WATER OSTRACOD FAUNA FROM LAKE DEPOSITS OF THE HOMO ERECTUS-BEARING KOCABAŞ LOCALITY (SW TURKEY), Acta Palaeontologica Romaniae 15 (2), pp. 41-69 : 2-5

Cyprideis torosa ( Jones, 1850)

1850 Candona torosa - Jones, 2, 6: 27; pl. 3: 6a-e.

1925 Cyprideis litto- - Sars, p. 9: 155; pls. 71, ralis nov. comb. 72:1.

1995 Cyprideis torosa - Tunoğlu et al., pl. 1, fig. Jones 1-5.

1996 Cyprideis torosa - Boomer et al., p.83, fig. 4, Jones J-N.

2000 Cyprideis torosa - Meisch, p. 459, fig. 188- Jones 189.

2005 Cyprideis torosa - Matzke-Karazs & Witt, p. Jones 128, pl. 3, fig. 8-11.

2012 Cyprideis torosa f. - Fuhrmann, p. 294, pl. torosa (Jones) 141, figs. 1 a-d, 2, 3 a-d, 4.

2013 Cyprideis ex. gr. - Stoica et al., p. 140, pl. 2, torosa (Jones) fig. 2-3.

Description. The carapace has a subovate shape in lateral view and a gently arched dorsal margin. Posterior and anterior margins are rounded. The greatest width of the carapace is slightly behind mid-length. The valves surface varies from having a fine reticulation to pitted ornamentation and can possess up to 7 phenotypic tubercles (nodes). Phenotypic tubercles are missing in the “un- nodded” specimens illustrated in Fig. 11 (1-4), but the general aspects of the fine ornamentation remain. Sexual dimorphism is occurring and female specimen appear higher and more rounded in the posterior area whereas the male carapace is narrower and much more pointed towards the posterior end. Dimension: Female: l = 1,06- 1,17 mm, h = 0,57- 0,63 mm, b = 0,50- 0,55 mm; Male: l = 1,10-1,12 mm, h = 0,57 – 0,60 mm.

Ecology. C. torosa is geographically widespread occurring and found in a wide range of salinities from almost freshwater to fully marine conditions. It also has been reported from hypersaline habitats and can be found in coastal ponds, lakes, lagoons or other marginal marine environments but has never been reported from deep marine habitats ( Meisch, 2000). It appears down to depth of 30 m and shows its maximal abundance between salinities ranging from 2 to 16.5 ‰ ( Wagner, 1964). It may constitute a significant portion of the biomass in brackish-water or hypersaline-alkaline, calcium-rich lagoons or inland lakes and the carapace remains can accumulate significantly in calcareous sediments of lagoons or lakes ( Benson, 1975). Today in the Sea of Azov, Cyprideis occurs in living populations of several hundred thousand specimens per square meter ( Caspers, 1957) and shows a similar population density in the Caspian Sea ( Benson, 1976).