Eudistoma circumvallatum is a solitary tunicate, a marine invertebrate belonging to the class Ascidiacea. This species, commonly found in a variety of marine environments, is characterized by its distinct morphology and ecological role within its habitat.
Description & Characteristics
Eudistoma circumvallatum typically exhibits a cylindrical or ovoid shape, with a maximum size reaching approximately 5 centimeters in length. The tunic, which is the outer covering of the animal, is smooth and transparent, allowing for a glimpse of the internal structures. The body is adorned with numerous small papillae, giving it a slightly textured appearance. The siphons, the openings for water intake and expulsion, are located at the anterior end of the body. The oral siphon, responsible for drawing in water, is often surrounded by a prominent ring of papillae, a characteristic feature of this species.
Habitat and Occurrence
Eudistoma circumvallatum is typically found in intertidal and subtidal zones, often inhabiting rocky substrates, seaweeds, and other marine debris. This species demonstrates a preference for temperate waters, with a depth range that extends from the intertidal zone to depths exceeding 20 meters. It is a common sight in coastal areas, particularly in the northeastern Pacific Ocean, where it contributes to the biodiversity of these marine ecosystems.
Taxonomy
Eudistoma circumvallatum belongs to the family Polycitoridae, a group of tunicates known for their colonial and solitary forms. It is classified within the order Aplousobranchia, a diverse order encompassing numerous species of ascidians. The class Ascidiacea, which encompasses Eudistoma circumvallatum, represents a group of marine invertebrates characterized by their sac-like bodies and filter feeding mechanisms.
Feeding
Eudistoma circumvallatum, like other ascidians, is a filter feeder. It draws in water through its oral siphon, passing it through a complex internal structure known as the pharynx. This structure is lined with numerous gill slits, which capture microscopic food particles, including plankton and algae. The filtered water is then expelled through the atrial siphon, completing the feeding process.
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