Salpe Géante

Overview

Salpa maxima, commonly known as the giant salp, is a transparent, barrel-shaped tunicate that drifts in the open ocean. Despite their jellyfish-like appearance, these organisms are chordates, sharing a closer evolutionary relationship to vertebrates than to cnidarians.

Appearance

These animals possess a gelatinous, transparent body that can reach lengths of over 10 cm. They exist in two distinct morphological forms: solitary, barrel-shaped individuals (oozooids) and colonial chains (blastozooids) that resemble floating garlands. A notable feature is the nucleus, a compact, often brightly colored mass containing the viscera, located at one end of the body.

Biology & behavior

Salps exhibit a complex life cycle characterized by an obligatory alternation of generations between solitary and colonial phases. They move through the water using a highly efficient form of jet propulsion, created by rhythmically contracting their bodies to pump water. This process serves a dual purpose: it provides locomotion and facilitates filter feeding. As they pump water, they strain out phytoplankton and other fine particles. By consuming these particles and producing sinking fecal pellets, they play a significant role in the ocean's biological pump, helping to transport carbon to the seafloor.