Aplidium ocellatum, commonly known as the “ocellated aplidium,” is a colonial tunicate belonging to the family Polyclinidae. This species is characterized by its distinctive appearance and widespread distribution in marine environments.
Description & Characteristics
Aplidium ocellatum colonies are typically encrusting and can reach up to several centimeters in diameter. They are composed of numerous individual zooids, each with a distinct body structure. Each zooid has a siphonal opening, which allows for water intake and expulsion. The colonies often display a vibrant orange or reddish-brown coloration, adding to their visual appeal.
Habitat and Occurrence
Aplidium ocellatum is a common inhabitant of intertidal and subtidal zones, primarily found on rocky shores and hard substrates. It is a euryhaline species, meaning it can tolerate a wide range of salinities. This adaptation allows it to inhabit diverse marine ecosystems, from coastal waters to the open ocean. The species is particularly abundant in the northeastern Atlantic Ocean, including the coasts of Europe and North Africa. It is also found in the Mediterranean Sea, where it plays a significant role in the marine food web.
Taxonomy
Aplidium ocellatum is classified within the phylum Chordata, specifically belonging to the class Ascidiacea. This class encompasses all tunicates, which are marine invertebrates that possess a sac-like body structure and a filter-feeding apparatus. Aplidium ocellatum is further classified within the order Aplousobranchia, a group characterized by the absence of a distinct branchial sac. Finally, it falls under the family Polyclinidae, a family known for its colonial lifestyle.
Feeding
Aplidium ocellatum is a filter feeder, meaning it obtains its nourishment by filtering microscopic particles from the surrounding water. Each zooid within the colony possesses a specialized feeding apparatus, including a siphon for water intake and a gill basket for capturing food particles. As water flows through the gill basket, plankton and other small organisms are trapped and ingested, providing the colony with essential nutrients.
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