laticaudata P.E. Müller, 1867

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 : 106

Ceriodaphnia laticaudata P.E. Müller, 1867

( Figs. 3–4 )

Length about 0.4–0.45 mm, width about 0.66–0.7 of length. In lateral view, ephippium asymmetrical, narrowing posteriorly; dorsal margin straight; ventral margin regularly curved from postero-ventral to anterior margin which is almost perpendicular to dorsal margin ( Figs. 3A, E , 4 A–D). Paired latero-dorsal ridges absent ( Figs. 3 B–C). A depression along dorsum separating two halves of ephippium well-visible; sculpture of dorsal plate as a few wavy longitudinal wrinkles and numerous spots of minute tubercles ( Figs. 3D, F ). Egg locule visibly extending laterally ( Figs. 3 B–C), without any wrinkles, but with numerous, densely located semicircular projections ( Figs. 3 E–H) well-visible also under optical microscope ( Fig. 4E ); a circular row of minute tubercles on each semicircular projection ( Fig. 3G ). Space between egg locule and dorsal margin with low, flattened projections (not associated with any air-spaces), bearing minute tubercles ( Fig. 3F ). Rest of ephippium surface covered by low, densely located flattened domes ( Fig. 3H ) – external signs of air-spaces which are well-visible under light microscope ( Figs. 4 C– F), each dome with a spot of minute tubercles. Ephippium with narrow ventral rim lacking any sculpture ( Fig. 3E ).

Figures

FIGURE 3. Ceriodaphnia laticaudata P.E. Müller, 1867, ephippial female from Cherepovetskoe Reservoir. A, lateral view of female. B, latero-dorsal view of ephippium. C, dorsal view. D, fragment of ephippium dorsal portion, dorsal view. E, ephippium. F, its dorsal portion, lateral view. G, sculpture of its central portion. H, ventral portion of ephippium. Scale bars: 0.1 mm for A–C, E; 0.01 mm for D, F–H.

FIGURE 4. Ceriodaphnia laticaudata P.E. Müller, 1867, ephippial female from Cherepovetskoe Reservoir. A–B, ephippial female with a single egg in ephippium, lateral view. C–D, opened ephippium, egg removed. E–F, its central and ventral portion. Scale bars: 0.1 mm.