Pegea confoederata (Pegea confoederata salp)


Cylindrical body shape, gelatinous exterior and transparent. Salps can be individual, but are mostly seen in colony chains up to a few meters long. The digestive tract can be seen inside the body as a red/orange colored sphere. On the outside of the salp there are muscle bands which help it contract and relax, allowing it to migrate vertically and filter feed. The number and positioning of these muscle bands is a guide to determining the species. Pegea confoederata zooids are straightly aligned in the aggregate phase and have few muscle bands. They form double rows of zooids, usually in a spiral coil form.


Unassessed by the IUCN Red list, but a circumglobal species of salp.


It can be found in any ocean or large sea, mostly known from the Atlantic, Mediterranean and the Indo-Pacific, in a depth range of 0-180 meters. It occurs more in warmer waters.


Salps have an alternating life cycle. The solitary life history phase, also known as an ozooid, is a single, barrel-shaped animal that reproduces asexually (budding or cloning) by producing a chain of tens to hundreds of individuals, which are released from the parent at a small size. The chain of salps is the ‘aggregate’ portion of the lifecycle. The aggregate individuals are also known as blastozooids; they remain attached together while swimming and feeding, and each individual grows in size. Each blastozooid in the chain reproduces sexually (the blastozooids are sequential hermaphrodites, first maturing as females, and are fertilized by male gametes produced by older chains), with a growing embryo oozoid attached to the body wall of the parent. The growing oozoids are eventually released from the parent blastozooids, and then continue to feed and grow as the solitary asexual phase, thus closing the lifecycle of salps.


Up to 10cm. per individual. A whole chain can measure up to several meters in length, and up to 2000 individuals.

Prey / Predation

Salps are non-selective filter feeders, producing water flow by alternately contracting its oral and anal muscle. Water flows in and phytoplankton – such as micro flagellates and diatoms – are filtered out.

Special features

Salps can reproduce very fast, enabling them to effectively multiply at the peak of phytoplankton blooms. When the phytoplankton bloom fades, so do the large number of salps. They are also very abundant in oceans and seas around the world and present a huge biomass, enough so to have an effect on the carbon-cycle of the oceans. Salps may look simple in form, but they do have a dorsal nerve cord, placing them high in the evolutionary ladder. Such primitive nerve cords are seen as predecessor to vertebrates with nervous systems.