Ceratium fusus (Ehrenberg) Dujardin 1841

Although direct toxicity has not been demonstrated, Ceratium fusus has been linked to the mortality of larval invertebrates.

Cells a very long drawn out apical horn. The left antapical horn is also very elongate while the right apical horn is extremely short.

The cell is fusiform with the epitheca tapering gently into a long, usually straight apical horn. The epitheca shows llinear markings. The hypotheca ends in a fully developed left antapical horn that can be curved or straight. The right antapical horn is greatly reduced.

C. fusus is found in oceanic to estuarine, predominantly coastal. It is found all around the UK. Cosmopolitan in cold temperate to tropical waters.

Salinity: 5-70 ppt