Adacna minima Ostroumov, 1907

van de Velde, Sabrina, Yanina, Tamara A., Neubauer, Thomas A. & Wesselingh, Frank P., 2020, The Late Pleistocene mollusk fauna of Selitrennoye (Astrakhan province, Russia): A natural baseline for endemic Caspian Sea faunas, Journal of Great Lakes Research 46 (5), pp. 1227-1239 : 1231

Adacna minima Ostroumov, 1907

( Fig. 4 : 2).

*1907 Adacna minima Ostroumov : 23, pl. 4, figs. 1–5.

1969 Adacna minima ostroumovi Logvinenko and Starobogatov : 338, fig. 354, 3.

2013 Adacna minima ostroumovi Logvinenko and Starobogatov, 1969 – Bogutskaya et al.: 378, fig. 146.

Dimensions – max. L 16.5 mm, H 12.7 mm.

Characterization – Relatively small subtriangular to subrounded Adacna ; shell thin, slightly more convex than other Adacna species and in outline resembling some Monodacna species, but hinge plate very thin, edentulous with the exception of juvenile stages where a small cardinal tooth in LV can be present that disappears in adult stages; dorsal margins usually more or less straight; ribs low, flat regularly spaced and fading towards anterior and posterior margins; in our material specimens with relatively well developed low ribs to almost smooth specimens and intermediates occur; well-developed growth bands in our material.

Ecology – Species occurs mainly in the middle and south-east of the CS, less often in the north CS ( Logvinenko and Starobogatov, 1969). Endemic species living in water with a salinity of at least 5–8 psu, preferably muddy, sandy-muddy and, rarely, sandy bottoms, mainly in the middle and south CS at depths of <40 m ( Bogutskaya et al., 2013).

Figures

Fig. 4. Cardiidae. (1) Adacna laeviuscula; (a) RGM.1309812 LV; (b) RGM.1309813 RV. (2) Adacna minima; (A) RGM.1309811 LV; (b) RGM.1309810 RV. (3) Monodacna semipellucida, RGM.1309802 RV; (4) Monodacna caspia s.l. (a) RGM.1309803 LV; (b) RGM.1309804 RV. (5) Hypanis plicata; (a) RGM.1309808 LV (b) RGM.1309809 RV. Scale bars = 1 cm.