A small Galapagos tambja, blue-green with dark markings, feeding on bryozoans.
Two to four centimetres. Dark blue with lighter blue bands running lengthways, each outlined in dark blue-black. There are five gill leaves, dark blue with lighter blue outer faces and thin light-blue inner edges. The ground colour is variable and ochre-turquoise, black and dark green animals have all been recorded.
Nothing else in the Galapagos looks like it, which makes the identification easy once you have seen one. Other members of the genus in the eastern Pacific are separated by the lengthways light-blue banding on a dark blue ground.
It is known only from the Galapagos. It eats bryozoans, and unusually for its genus it takes encrusting colonies rather than branching ones, which is a genuinely useful thing to know when looking for it. It lives between about 4 and 18 m.
The common name is usually written Mulliner’s nudibranch, after the shell collector David Mulliner.
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.
