Silverline system, ventrolateral view

Description:

Silverline system (ventrolateral view) of the cinetochilid scuticociliate, Sphenostomella vernalis (Dragesco and Groliere, 1969) Jankowski, 1980 (synonym: Sathrophilus vernalis). The cell is elongate ovoid. The many large mucocysts give the cell a yellowish-orange color when viewed by brightfield illumination. The roughly triangular peristome is in the anterior 1/3. There are 31-34 longitudinal somatic kineties. There are two left postoral kineties and one right postoral kinety (K1). There is a cluster of unciliated kinetids (scutica) adjacent to the posterior margin of the peristome (visible here). There is a short preoral suture and a longer broader postoral suture. The cleft-like cytoproct (visible here as a thick dark longitudinal line)is located in the ventral midline in the posterior suture between the excretory pore of the contractile vacuole (visible here) and the posterior margin of the peristome. There are prominent transverse fibrils between the 2nd and 3rd right somatic kineties as they diverge anteriorly (seen here anterolateral to the peristome). There is a semicircular undulating membrane on the right margin of the peristome. There are three adoral membranelles. The M1 is an obliquely oriented group of 3 kineties. Its hook-shaped anterior end nearly reaches the anterior end of the undulating membrane. The M2 lies parallel to and is longer than M1 and also has a hook-shaped group of kinetids at its anterior end. M3 has broad “U” shape directed anteriorly. Fibrils (seen here)radiate from the posterior margin of the peristome toward the cytostome. Between every two primary meridians (heavier longitudinal black lines) there is one secondary meridian. The primary and secondary meridians are connected at irregular intervals by transverse silverlines. Collected from polysaprobic standing ditchwater at several different sites near Boise, Idaho March 2005. stained by the dry silver nitrate technic (see Foissner, W. Europ. J. Protistol., 27:313-330;1991).Brightfield.