''Salpa fusiformis'', sometimes known as the common salp, is the most widespread

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), ...

salp A salp (: salps, also known colloquially as “sea grape”) or salpa (: salpae or salpas) is a barrel-shaped, Plankton, planktonic tunicate in the family Salpidae. The salp moves by contracting its gelatinous body in order to pump water thro ...

. They have a

cosmopolitan distribution In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and en ...

, and can be found at depths of . They exhibit

diel vertical migration Diel vertical migration (DVM), also known as diurnal vertical migration, is a pattern of movement used by some organisms, such as copepods, living in the ocean and in lakes. The adjective "diel" ( IPA: , ) comes from , and refers to a 24-hour ...

, moving closer to the surface at night. They can occur in very dense swarms, as solitary

zooid 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 ...

s or as colonies. Solitary zooids usually measure in length. They are barrel-shaped and elongated, with a rounded front and a flat rear. Aggregate zooids are in length individually (excluding projections). They are usually barrel or spindle-shaped.

Economic effects

The incursion of a large number of ''Salpa fusiformis'' into the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

in 1920 led to a failure of the Scottish herring fishery.Scottish Fisheries During the War in

References

Salpidae Animals described in 1804 Taxa named by Georges Cuvier Cosmopolitan animals {{Tunicata-stub