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
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
A long thin shaped Ceratium. From a swollen body the apical horn
is long, slightly tapers and has a slight curve. The hypothecal
horns are asymmetric, one is rudimentary, the other is long,
slightly tapers and has a slight curve.
This species is very similar to C. extensum the difference lie in
the length (C. fusus <500µm) and the distribution with C. fusus
occuring in warmer waters.
|CPR:121||ITIS:10400 ||WORMS:109951 |
Distribution and Abundance