E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Psolus chitonoides is an unusual species that resembles a chiton rather than a typical sea cucumber. It is dome-shaped, and covered with pale yellow to bright orange, shinglelike calcareous plates; about four rows between the mouth and anus. The sole is soft, flat and pale orange to white. The body is oval, and can grow up to 7 cm long and 5.8 cm wide. A plume of 10 equal-sized, bright red, white-tipped tentacles, protrudes through an opening in the dorsal plates at one end. Tube feet are confined to the sole. A series of two to four rows of robust tube feet run down each side of the sole; and another row of tiny tube feet in small depressions run down the outer edge of the sole. A staggered series of tube feet runs down the centre of the sole.

Skin ossicles: one type of circular perforated plate - some with knobs coalesced into a raised network - occur only in the ventral sole.

There are two species similar to Psolus chitonoides: Psolidium bidiscum and Psolus squamatus. P. bidiscum is smaller (1 to 3 cm), and is normally dredged from deeper water. It has tube feet piercing the dorsal scales; and the tentacles are pale pink or white, as opposed to the bright red, white-tipped tentacles of P. chitonoides. Psolus squamatus has white scales and is dredged from deeper waters.