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 (biology), cell, that has a specific function. The name ''organelle'' comes from the idea that these structures are parts of cells, as Organ (anatomy), organs are to th ...

found in some

dinoflagellate The Dinoflagellates (), also called Dinophytes, are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered protists. Dinoflagellates are mostly marine plankton, but they are also commo ...

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 (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

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 An ocelloid is a subcellular structure found in the family (biology), 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 e ...

and

nematocyst A cnidocyte (also known as a cnidoblast) is a type of cell containing a large secretory organelle called a ''cnidocyst'', that can deliver a sting to other organisms as a way to capture prey and defend against predators. A cnidocyte explosively ...

. 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