Aplidium coronum is a colonial tunicate, a type of marine invertebrate belonging to the family Polyclinidae. These small, often brightly colored organisms form colonies that can be found in a variety of marine environments.
Description & Characteristics
Colonies of Aplidium coronum can reach a maximum size of about 10 centimeters in diameter. The individual zooids, or members of the colony, are typically only a few millimeters in length and are embedded in a gelatinous matrix. The colony often takes on a rounded or irregular shape, and its surface is covered in numerous, small, star-shaped openings known as siphons. The color of the colony can vary, but it is often a vibrant orange, yellow, or red.
Habitat and Occurrence
Aplidium coronum is a common inhabitant of intertidal and subtidal zones, typically found attached to rocks, shells, and other hard substrates. It is a particularly prevalent presence in the northeastern Atlantic Ocean and the Mediterranean Sea, where it can be found in a range of depths, from the shallow intertidal zone to depths of around 20 meters. This species is often found in the infralittoral zone, a marine zone characterized by rocky shores and abundant seaweed. It may also occur in the circalittoral zone, which is characterized by deeper water and a greater abundance of sediment.
Taxonomy
Aplidium coronum belongs to the Class: Ascidiacea, Order: Aplousobranchia, and Family: Polyclinidae. Ascidiacea is a diverse class of marine invertebrates that includes both solitary and colonial forms. The order Aplousobranchia comprises a group of tunicates characterized by their simple internal anatomy and lack of a distinct branchial sac. The family Polyclinidae includes a wide range of colonial tunicates, many of which are brightly colored and form intricate colonies.
Feeding
Like all tunicates, Aplidium coronum is a filter feeder. The zooids in the colony draw water through their inhalant siphons, which are lined with numerous cilia. These cilia create a current that draws water into the zooid, where it passes through a fine mesh-like structure called the branchial basket. As water flows through the branchial basket, food particles such as phytoplankton and bacteria are trapped and transported to the digestive system. The filtered water is then expelled through the exhalant siphon.
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