Taxonomy

Adult orange-tipped sea squirts generally measure 2–4cm but can be up to 8cm in the northern hemisphere and grow considerably larger in the southern hemisphere - up to 15cm.

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