Size and Shape: Generally no more than 50 µm long, the 'verruculosa-like' variety tends to be smaller, peaking at ~ 25-30 µm long.  Usually tear-shaped with 2 subapical flagella and mucocysts arranged radially around the cell cortex giving the cells a 'lumpy' appearance.

Plastids and Pigments: Many green or yellow-green plastids, chla, c1 and c2; ß-carotene and fucoxanthin as accessory pigments.

Distinguishing features: Pointed posterior end and lumpy texture.  Ejected mucocysts are shaped like oboes.

Distribution: Worldwide in brackish waters.  Chattonella is fragile and easily overlooked if not in a dense bloom.

Impact: Toxic, both species have been shown to produce brevitoxins and are responsible for numerous fish kills.

References: 

Lewitus, A.J., Schmidt, L.B., Mason, L.J., Kempton, J.W., Wilde, S.B., Wolny, J.L., Williams, B.J., Hayes, K.C., Hymel, S.N., Keppler, C.J., and Ringwood, A.H. (2003) Harmful algal blooms in South Carolina residential and golf course ponds. Population and Environment. 24: 387-413.

Biecheler, B. 1936. Sur une Chloromonadine nouvelle d'eau saumatre. Chattonella subsalsa gen., n. sp. Archiv. Zool. Exper. Gen. 78:79–83. 

Okaichi, T. 1985. Fish kills due to the red tides of Chattonella. Bull. Mar. Sci. 37:772. 

Onoue, Y. and K. Nozawa 1989. Separation of toxin from harmful red tides occurring along the coast of Kagoshima Prefecture. In: Red tides: Biology, Environmental Science and Toxicology. T. Okaichi, D.M. Anderson and T. Nemoto (eds.). Elsevier. Holland.