Bmc evol bio hoppenrath Erythropsidinium ocelloid piston fig1r

A piston (also known as a dart, prod, or tentacle) is a complex contractile

organelle In cell biology, an organelle is a specialized subunit, usually within a cell, that has a specific function. The name ''organelle'' comes from the idea that these structures are parts of cells, as organs are to the body, hence ''organelle,'' the ...

found in some

dinoflagellate The dinoflagellates (Greek δῖνος ''dinos'' "whirling" and Latin ''flagellum'' "whip, scourge") are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered algae. Dinoflagellates are ...

s, namely the ''

Erythropsidinium ''Erythropsidinium'' (formerly ''Erythropsis'') is a genus of dinoflagellates (a type of unicellular eukaryote) of the family Warnowiaceae. Characteristics ''Erythropsidinium'' cells are a relatively large by dinoflagellate standards (50-120μm ...

'' and '' Greuetodinium''

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

of the family Warnowiaceae. This group is also well known for possessing other unusually complex subcellular structures such as the

ocelloid An ocelloid is a subcellular structure found in the family Warnowiaceae (warnowiids), which are members of a group of unicellular organisms known as dinoflagellates. The ocelloid is analogous in structure and function to the eyes of multicellul ...

and

nematocyst A cnidocyte (also known as a cnidoblast or nematocyte) is an explosive cell containing one large secretory organelle called a cnidocyst (also known as a cnida () or nematocyst) that can deliver a sting to other organisms. The presence of this ce ...

. Observations of ''Erythropsidinium'' samples reveal that the length of the piston is highly variable across specimens. The piston is known to be capable of repetitive and dramatic contractile motion; although its function is unknown, roles in locomotion, prey capture, and defense have been suggested.

References

Organelles {{microbiology-stub