Dinoflagellate

Ceratium macroceros

(Ehrenberg, 1840) Vanhöffen, 1897

Description

The Ceratium genus is most distinguished by the characteristic arms or horns. These help the Ceratium float; but also prevent them from moving too quickly. The horns tend to be shorter and thicker in cold, salty water, and longer and thinner in less salty, warmer water.

Ceratium are covered by an armour-like cell wall or theca, composed of many textured plates, this can easily been seen on CPR samples.

In living cells Ceratium have two flagella, a transverse flagellum beats in a spiral motion, and a longitudinal flagellum pulses in waves. The grooves in which the flagella operate are prominently seen in this species.

Ceratium are relatively harmless organisms. They are non-toxic and are necessary for the food web. However, they can cause a red tide if conditions allow for excessive blooming. While this red tide is not toxic, it can deplete resources in its environment, and causes a strain on the ecosystem. In general though, Ceratium are necessary components of their habitats. They serve not just as nutrients for larger organisms, but they keep smaller organisms in check through predation. Ceratium are mixotrophs; obtaining food both through photosynthesis and phagocytosis.  (Information from Tomas 1996, Microbewiki and Britannica online encyclopedia).

Ceratium macroceros

A large pentagon shaped cell, whose cell  body is small in proportion to the horns. The off-set apical horn is long and slender. The hypothecal horns are open, they extend down away from the hypotheca before curving round and extending diagonally from the apical horn; this gives the hypotheca a bucket shaped indent. One hypothecal horn extends almost parallel with the off-set apical horn, the other more strongly angled away.



CPR:125ITIS:10403 WORMS:109967

Distribution and Abundance

Distribution 1958-1999







Image Identification not guaranteed. Contact gbrice@sahfos.ac.uk - last updated on Tuesday, November 16, 2010