One of the small lined hypselodorids, separated on where the yellow marks sit.
A small chromodorid, usually 2 to 3 cm, the mantle white to pale blue-white with a pair of dark blue to black lines running the length of the back and a row of yellow to orange marks between them. A fine yellow line runs round the mantle edge, and the rhinophores and gill plume are orange to red. Several small lined Hypselodoris share this scheme, and what separates them is the number and position of the yellow marks relative to the dark lines — detail that shows in a photograph taken square from above and is usually lost in an oblique one. Hypselodoris infucata is the easy one to rule out: its ground is green-yellow and speckled, with blue spots rather than lines.
Hypselodoris maridadilus carries a comparable pattern but is an East African and Indian Ocean animal, so a lined hypselodoris of this kind in the Coral Triangle is not that species, whatever an older caption says.
Like the rest of the genus it feeds on dysideid sponges and stores their sesquiterpenes in glands around the mantle margin, which accounts for its moving about uncovered in daylight. Pairs and coiled white egg ribbons are found on the food sponge. Recorded from about 5 to 25 m on sponge-covered rubble.
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.
