Biology

The animal is dark brown to blue in ground color with a bright orange marginal band on the parapodia. Stripes and/or spots on the outer parapodial surface and head are white, yellow, and/or light blue. The inner parapodial surface is iridescent blue and the parapodial flaps are held over the body in life. The parapodial color pattern is highly variable in this species. Rhinophores are rolled and large with a white stripe merging at the head that makes a “Y” shape. The pericardium is short and round with (usually) one pair of dorsal vessels branching from its posterior side. The sole of the foot has a transverse division that divides it. The anus opens to the right of and anterior to the pericardium (Jensen, 1992).

This species is brightly colored but not cryptic and is often found crawling on substrates other than the algae they eat (Gosliner, 1995).