Ceratium furca (Ehrenberg) Claparède & Lachmann 1859

Is a red tide species that can cause death via nutrient capture and anoxia. It is also been reported to produce paralytic toxins (Vargas-Montero & Freer 2004).

Ceratium furca has a very prominent fairly straight apical horn, it also has two unequally sized posterior horns with a thin bar which connects the two. The right horn is shorter than the left and both are serrated. It has a fairly wide girdle. Thecal plates are moderately thick with regular reticulum of ridges with pores in the depressions (Tomas et al. 1997).

Ceratium furca has a fairly wide girdle, a very prominent fairly straight apical horn, it also has two unequally sized (the left horn is longer than the right) posterior horns with a thin bar which connects the two. It is yellow with a brown tint when unstained (Tomas et al. 1997).

This is a fairly cosmopolitan pelagic species with regular reports of blooms forming in Japan and The Americas. It has also been reported in the North Sea, the Mediterranean and the Dardanelles (Gomez 2003; Jansen 2006; Turkoglu 2008)

Temperature and salinity range varies with area. Smalley & Coates (2002) suggest a temperature optimum of 24 - 27°C and salinity at 15psu. Guerra-Martínez & Lara-Villa (1996) suggest optimums of 13-35psu and 30-34°C on a Mexican strain. Nordi (1953) reports optimums of 20-25psu and 20°C.