White crust covering a Spisula shell. Collected via scallop dredge.
Similar in appearance to Didemnum albidum, perhaps. No microscopy done.
Intertidal at Otstoia Island. Under rock
Ascidiacea (commonly known as the ascidians or sea squirts) is a class in the Tunicata subphylum of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer "tunic" made of the polysaccharide tunicin, as compared to other tunicates which are less rigid.