Raspberry Ascidian – Didemnum cuculliferum

The Raspberry Ascidian, scientifically known as Didemnum cuculliferum, is a colonial tunicate that belongs to the family Didemnidae. It is characterized by its distinctive raspberry-like appearance, due to its numerous, small, bright red or pink lobes. These lobes, also known as zooids, are joined together to form a common tunic, giving the colony its distinctive, almost fleshy look.

Description & Characteristics

Didemnum cuculliferum is a filter feeder, drawing in water through siphons and filtering out plankton and other small organisms. This makes it a crucial part of the marine food web, providing sustenance for larger animals. The colony can grow to a considerable size, typically reaching several centimeters in diameter. It can be found in a variety of colors, ranging from bright red to pink, depending on its environment and feeding habits.

Habitat and Occurrence

Didemnum cuculliferum is a common inhabitant of coastal waters, particularly in the intertidal zone and shallow subtidal habitats. It can be found attached to various substrates, including rocks, shells, and seaweed. This species prefers sheltered areas with moderate water flow, making it a common sight in bays, estuaries, and harbors. It is typically found in the neritic zone, a marine zone extending from the shoreline to the edge of the continental shelf, and the intertidal zone, which is the area between high and low tide marks.

Taxonomy

The species Didemnum cuculliferum belongs to the Class: Ascidiacea, Order: Aplousobranchia, and Family: Didemnidae. These classifications are based on the evolutionary history and shared anatomical features of these organisms, placing Didemnum cuculliferum within a complex and diverse group of marine invertebrates.

Feeding

Like other ascidians, Didemnum cuculliferum is a filter feeder, consuming plankton, a diverse mix of small organisms drifting in the water. The individual zooids, which make up the colony, draw in water through their siphons, trapping food particles on a mucus-coated net. These trapped particles are then transported to the digestive system, providing nutrients for the colony’s growth and survival.