Abramis bjoerkna ( Linnaeus, 1758 )

Schulz-Mirbach, Tanja & Reichenbacher, Bettina, 2006, Reconstruction of Oligocene and Neogene freshwater fish faunas-an actualistic study on cypriniform otoliths, Acta Palaeontologica Polonica 51 (2), pp. 283-304 : 289

Abramis bjoerkna ( Linnaeus, 1758)

Fig. 4 .

Material and dimensions.—See Table 2.

Description.—The general shape is semicircle−like in the anterior portion and tapering to a rounded tip in the posterior portion. In the largest specimens ( Fig. 4C, D ), all edges are well developed; but the antero− and posteromedial edges are rounded and rather indistinct in the smaller lapilli. In all specimens, the anterolateral edge is well developed, whereas the posterolateral edge is less pronounced, but also distinct. The medial margin is more or less straight in the large specimens and faintly rounded in the smaller ones. The posterior and lateral margins are oblique and may be slightly crenulated.

Figures

Fig. 4. Utricular otoliths (lapilli) of Recent Abramis bjoerkna (Linnaeus, 1758) from wild catches in Germany. A, B, D. BSPG 2003 IV 161, 43, and 41 respectively, in dorsal (A, B and D1 are mirrored) and anterior (D2) views. C. BSPG 2003 IV 42 in ventral view. All lapilli are represented as right ones, except for C and D2, which are represented as left ones (C is mirrored). SEM−pictures (C, D), digital photographs (A, B).