FIGURE 1 in Morphology and infraciliature of the oligotrich ciliate Strombidium rapulum (Yagiu, 1933) Kahl, 1934 (Protozoa, Ciliophora, Oligotrichida) from the intestine of sea urchin Hemicentrotus pulcherrimus Agassiz

FIGURE 1. Strombidium rapulum from live cells (A, B, D, E – G) and after protargol impregnation (C, E, H, I). (A) Ventral view of a representative specimen, arrowheads mark the cilia of ventral kinety. (B) To show the creeping state, note the cell attached to the substrate with its adoral membranelles. (C) To demonstrate variations in macronucleus shape. (D) Swimming trace. (E) Apical view of the buccal apparatus, arrowheads note argentophilic fibres. (F, G) Ventral view of specimens (from Yagiu 1933 and Poljansky 1951, respectively). (H, I) Ventral and dorsal view of same specimen, to show the infraciliature, arrowhead in H marks the pharyngeal fibres. AM = anterior membranelles; AP = apical protrusion; EM = endoral membrane; GK = girdle kinety; Ma = macronucleus; VK = ventral kinety; VM = ventral membranelles. Scale bars in (A, G – I) = 40 µm, in (F) = 50 µm