Ceratium hirundinella

Portrait of the dinoflagellate, Ceratium hirundinella (O.F. Müller) Schrank, 1882. The body is drawn out into a long anterior horn and three subequal posterior horns at angles to one another. The transverse girdle or cingulum bears a flagellum (not seen in this image), which differs structurally from the trailing flagellum (seen here between the right and central posterior horns). Complex faceted cellulose plates cover the body. Small discoid plastids contain chlorophyll a and c along with other pigments, which may give a yellow-brown or brownish-red color. Composite image. Collected from freshwater pond near Boise, Idaho September 2003. DIC optics.

Ceratium hirundinella is one of the larger dinoflagellates (length ~ 400 μm) occurring in Lake Kinneret. It is easily identified by its typical 3 or 4 horns of varying length and overall shape reminiscent of the Eiffel tower. It is abundant in spring, when it accompanies the more abundant dinoflagellate Peridinium gatunense at its bloom decline phase. At this time of year other, smaller dinoflagellates are also present in the water column (Peridiniopsis elpatiewsky, Ps. cunningtonii, Ps. borgei, Ps. polonicum). While usually less abundant than the other dinoflagellates, it produces a large number of cysts (resting spores) that sink to the sediments. An exceptional bloom of Ceratium occurred in spring 1993 when cell densities in the upper 0-2 m layer reached 150/mL.