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,'' t ...

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'' 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 ...

of the family

Warnowiaceae The Warnowiaceae are a family of athecate dinoflagellates (a diverse group of unicellular eukaryotes). Members of the family are known as warnowiids. The family is best known for a light-sensitive subcellular structure known as the ocelloid, a h ...

. This group is also well known for possessing other unusually complex subcellular structures such as the ocelloid 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 c ...

. 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