Ascidie Noire

Overview

Phallusia fumigata, commonly known as the black sea squirt, is a solitary tunicate found primarily in the Mediterranean Sea and parts of the Atlantic Ocean. This marine invertebrate is recognized by its distinct, dark-colored body and is typically observed as a solitary individual rather than in colonies.

Distribution & habitat

This species is widely distributed across the Mediterranean and the eastern Atlantic, ranging from the coast of Portugal down to Cape Verde. It inhabits a variety of environments, including rocky reefs, coralligenous substrates, and sandy or muddy bottoms. While it can be found from shallow surface waters down to depths of approximately 100 meters, it is generally not found in coastal lagoons.

Appearance

The black sea squirt is characterized by a thick, cartilaginous, and opaque tunic that ranges in color from a glaucous green to deep anthracite black. Its surface is typically smooth or slightly mamillated (bumpy). The animal is often fixed to the substrate on its left side. It features a prominent oral siphon at its summit for water intake, while the cloacal siphon is often less conspicuous or difficult to observe. Depending on the region, individuals can reach heights between 8 cm and 15 cm.

Biology & behavior

As a filter feeder, this tunicate survives by drawing water through its oral siphon, passing it through internal branchial structures to trap nutrients before expelling the filtered water through the cloacal siphon. It is known to occupy rock crevices, sometimes retracting its siphons rapidly when disturbed, which can make it challenging to spot in its natural environment.