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

Cheiraster dawsoni is a spiny vermilion sea star with five arms up to 17 cm long. The ratio of arm to disc is from 5.0 to 5.5. The larger aboral plates bear a large central spine surrounded at the base by a circle of 2 to 8 unequal spinelets; the smaller plates bear 1 to 12 spinelets. Papulae are absent from the centre of the disc, the aboral interradial area and the outer two-thirds of the arm; there are 3 to 8 pectinate pedicellariae on proximal half of each arm. The superomarginals and inferomarginals are staggered (not opposite each other). The superomarginals bear 2 stout tapering spines, and around each spine is a circle of 12 to 15 slender spinelets. The inferomarginals have 3 or 4 rigid tapering spines surrounded by auxiliary spinelets that are one-third the length of the spine. The oral interradial area has a few plates with small, well-spaced spinelets, 1 or 2 tapering spines and 1 to 3 pectinate pedicellariae. The adambulacrals are wider than their length; the curved furrow margin bears 4 to 7 spinelets, of which the central 3 or 4 are longer than the width of the plate; the oral surface has a transverse series of 2 or 3 long, slender spines, with a few spinelets around the edge. Mouth plates have 6 to 8 marginal spines, the apical spine being the largest, and 7 to 10 suborals.

Above 200 metres depth, this species is very distinctive in shape and surface detail. In depths greater than 200 metres it might be confused with Nearchaster or Benthopecten species.