Didemnum perlucidum

Didemnum perlucidum is a colonial tunicate species belonging to the family Didemnidae, commonly known as a compound ascidian. It forms extensive, gelatinous mats that can cover surfaces in marine environments. These mats can be found in a variety of colors, ranging from white to yellow and even orange.

Description & Characteristics

Didemnum perlucidum colonies can reach a maximum size of several centimeters in diameter. They are typically characterized by their translucent, gelatinous texture and their smooth, even surface. Individual zooids within the colony are small and embedded within the common tunic, making them difficult to distinguish with the naked eye. The zooids have two siphons, an incurrent siphon for drawing in water, and an excurrent siphon for expelling filtered water.

Habitat and Occurrence

Didemnum perlucidum is a common inhabitant of shallow marine environments, primarily in the intertidal and subtidal zones. It is often found attached to hard substrates such as rocks, piers, and artificial structures. This species can also be found on seagrass and macroalgae, particularly in areas with high levels of organic matter. Its preference for shallow waters makes it a prevalent species in the neritic zone. Didemnum perlucidum has a broad geographical distribution, being found in coastal areas of the Atlantic Ocean, including the Mediterranean Sea and the Caribbean.

Taxonomy

Didemnum perlucidum belongs to the class Ascidiacea, which encompasses a diverse group of filter-feeding marine invertebrates. Within this class, it is classified under the order Aplousobranchia, characterized by their simple gill structure. The family Didemnidae, to which Didemnum perlucidum belongs, is known for its colonial nature, with individual zooids living within a shared tunic.

Feeding

Didemnum perlucidum, like other tunicates, is a filter feeder. It draws water into its incurrent siphon, capturing small particles of food such as phytoplankton and detritus using a mucous net. The filtered water is then expelled through the excurrent siphon. This feeding strategy contributes to the species’ ecological role as a primary consumer in marine ecosystems.