pulchella Sars, 1862

Kotov, Alexey A., Ibragimova, Aisylu G. & Neretina, Anna N., 2018, Identification of Ceriodaphnia Dana, 1853 (Crustacea: Cladocera) taxa from European Russia based on ephippial morphology, Zootaxa 4527 (1), pp. 105-123 : 115-118

Ceriodaphnia pulchella Sars, 1862

( Figs. 9–10 )

Length about 0.35 mm, width about 0.7 of length. In lateral view, ephippium semicircular; dorsal margin straight; ventral margin regularly curved from postero-ventral to antero-ventral angle ( Figs. 9A , 10 A–C). Paired latero-dorsal ridges absent ( Figs. 9 B–C). A depression along dorsum separates two halves of ephippium well-visible; sculpture of dorsal plate without any wrinkles, with numerous low spots covered by minute tubercles ( Fig. 9D ). Egg locule very slightly extends laterally, without any wrinkles, in general smooth ( Fig. 9C ), but bearing minute tubercles sometimes organized into spots ( Fig. 9E ), probably these spots make locule surface non-transparent under light microscope ( Figs. 10 D–D). Space between egg locule and dorsal margin with same sculpture. The rest of ephippium with obscure (under SEM) polygonal reticulation ( Fig. 9F ) – external sign of air-spaces which are well-visible under light microscope ( Figs. 10 D–F); lines of reticulation with especially minute tubercles. Ephippium has a very narrow ventral rim with obscure reticulation, lacking any tubercles ( Figs. 9F , 10F ).

Note that in our material the ephippia were unusually small as compared to previous descriptions ( Jaksch 1992).

Figures

FIGURE 9. Ceriodaphnia pulchella Sars, 1862, ephippial female from a pond in stadium of AZLK factory near Metro Station "Textilshchiky", Moscow city. A, lateral view of female. B, dorsal view of ephippium. C, antero-lateral view. D, fragment of ephippium dorsal portion, lateral view. E, sculpture of its central portion. F, postero-ventral portion of ephippium. Scale bars: 0.1 mm for A–C; 0.01 mm for D–F.

FIGURE 10. Ceriodaphnia pulchella Sars, 1862, ephippial female from a pond in stadium of AZLK factory near Metro Station "Textilshchiky", Moscow city. A–B, ephippial female with a single egg in ephippium, lateral view. C–D, opened ephippium. E–F, its dorsal and ventral portion. Scale bars: 0.1 mm.