White, with orange-lined ridges and black spots in the spaces between them.
A firm-bodied dorid to about 6 cm, white to translucent cream, with a network of low ridges raised over the back and a scatter of dark spots. The crests of the ridges carry a yellow to orange line and the mantle margin is edged in the same colour; the spots are small, round and black to dark brown, and they sit in the flat spaces enclosed by the ridges rather than on the crests. Those spots are what separates this animal from Halgerda batangas, which has the same ridge network and the same orange lines but no spotting between them. The gill and the rhinophores are dark, streaked orange to brown-black.
Several Halgerda occur here and they are separated on the arrangement of the ridges and the colour of the lines along them, so a photograph taken square to the back is worth more than one taken from the side. The body is noticeably harder than a chromodorid’s, which is normal for the genus: it holds its shape rather than flowing over the substrate.
Feeds on sponges, and is usually out in the open on the sponge it is eating rather than under cover, on rubble, dead coral and rock rather than on soft sediment. Recorded from about 5 to 30 m through the central Indo-Pacific.
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.
