''Pyrosoma'' is a genus of

pyrosome Pyrosomes are free-floating colonial tunicates in family Pyrosomatidae. Pyrosomes consist of colonies of small Zooids. There are three genera, '' Pyrosoma'', '' Pyrosomella'' and '' Pyrostremma'', and eight species. They usually live in the uppe ...

s, marine colonial

tunicate Tunicates are marine invertebrates belonging to the subphylum Tunicata ( ). This grouping is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time ...

s in the class

Thaliacea Thaliacea is a class of marine chordates within the subphylum Tunicate, Tunicata, comprising the salps, pyrosomes and doliolids. Unlike their benthic relatives the Ascidiacea, ascidians, from which they are believed to have emerged, thaliaceans a ...

. It contains four

pelagic The pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the sur ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

found in temperate waters worldwide. Pyrosomes are filter feeders that uniquely use a type of continuous jet propulsion, generated by individual

zooids A zooid or zoöid is an animal that is part of a colonial animal. This lifestyle has been adopted by animals from separate unrelated taxa. Zooids are multicellular; their structure is similar to that of other solitary animals. The zooids can ...

, to slowly move forward while grazing; the species ''P. atlanticum'' has the highest known food clearance rate among zooplankton grazers. Colonies can reach lengths of up to .

Species

The genus contains four recognized species:

References

Pyrosomatidae Tunicate genera Taxa described in 1804 Taxa named by François Péron {{Tunicata-stub