Purple lines down a translucent body, and it stores the hydroid's stings in its cerata.
An aeolid to about 3 cm, the body translucent white to pale pink and carrying fine magenta to purple-red longitudinal lines — one along the midline and one down each side — which is what the name refers to. The cerata are set in clusters along the back, each with a red-brown to orange core where the digestive gland shows through, and an opaque white tip. The rhinophores are annulated, ringed along their length, which separates Coryphellina from several similar aeolids with smooth rhinophores. Against Coryphellina exoptata, which is on the same hydroids: exoptata has no body lines, and its cerata are banded purple at the base, orange in the middle and white at the tip along their whole length rather than carrying a single core colour.
Both species have moved between Flabellina and Coryphellina in recent revisions and both names remain in circulation, so a guidebook giving Flabellina rubrolineata is describing this animal.
Feeds on hydroids and does what aeolids do with them: the stinging cells of the prey pass undischarged through the gut, are carried to sacs at the tips of the cerata and are held there for the slug’s own defence. Found on hydroid colonies on rubble, wreckage and jetty structure from about 3 to 25 m, usually with white spiral egg coils on the same colony.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
