The choreotrichs are a group of small marine

ciliate The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagellum, eukaryotic flagella, but are in general shorter and present in much larger numbers, with a ...

s. Their name reflects the impression that they appear to dance ('choreo' as in choreography). The group includes the

tintinnid Tintinnids are ciliates of the choreotrich order Tintinnida, distinguished by vase-shaped shells, the name deriving from a Latin source meaning a small tinkling bell, that are called'' loricae'', which are mostly protein but may incorporate min ...

s, which produce species-specific loricae (shells), and are important because these may be preserved as microfossils. The cyst forms have been suggested to be affiliated to Chitinozoans, although other studies suggest Chitinozoans to have affinities to larger marine animals, and not tintinnids. Often they have been included among the

oligotrich The oligotrichs are a group of ciliates, included among the spirotrichs. They have prominent oral cilia, which are arranged as a collar and lapel, in contrast to the choreotrichs where they form a complete circle. The body cilia are reduced to ...

s. Tintinnids seem to be an excessively specious group as over 400 living species have been described, based on characteristics of the lorica or shell. Choreotrichs (including tintinnids) are part of the microzooplankton. Generally small (20–200 micrometres in size) organisms found in the plankton. They feed on small algae and serve as prey for larger organisms in the plankton such as copepods and larval fish.

References

Spirotrichea {{ciliate-stub