Taxonomy

It has several distinguishing features:

• it lays flat on the substrate attached along its right side
• coloration can vary significantly, ranging from transparent, white, brown to various shades of orange
• its siphons are usually orange, although not always
• the tunic is smooth and often clean, but can be covered in microbial film or overgrown by other species, including compound ascidians
• it can mould its body shape into the available space between the adjoining sessile fauna; however on open substrate it grows into an oval shape
• the inhalant siphon is normally at the extreme end of the body
• the exhalant siphon is characteristically between a quarter and half-way down the body, and slightly on the right
• Corella eumyota cannot retract its siphons
• the hind-gut forms a simple curve following the contour of the posterior end of the body

Look-alikes
In Europe, Corella eumyota can be confused with species of Molgula (sea grapes). These tunicates, like Corella eumyota, are semi-translucent, often form dense clumps and are approximately the same size. Molgula spp. typically have:

• more spherical body shapes
• both siphons positioned at the top of the body
• an S-shaped gut