Cuthona rubescens

Picton & Brown, 1978

This small species (up to 12 mm in length) resembles Cuthona amoena in some ways, but there are consistent differences in pigmentation. The body is translucent and white, with the opaque white ovotestis and the brown jaws visible through the skin. Small groups of opaque white speckles are scattered over the back, mainly in front of the ceratal bases. The rhinophores are streaked on the rear face with opaque white surface pigment, interrupted by a crimson band. The oral tentacles lack the crimson bands. The dorsal surfaces of the cerata exhibit a basal crimson patch and scattered white blotches, often concentrated apically. The hepatic lobes may be brown or olive-green. The cerata are set in up to eleven rows with up to six cerata in each half-row.

All the British records have come from shallow subtidal areas, from 10-30 m. The usual diet is the hydroid Halecium halecinum .

This species has been recorded from scattered localities all around the British Isles, but not elsewhere (Distr. C. rubescens).