Opisthobranch of the Week Data
Halgerda brunneomaculata is considered to be very rare on Okinawa; the above featured animal is the only known specimen from Okinawa as of this date (November, 1999). The animal was found crawling in a shaded portion of a live stony coral reef (predominantly made up of Acropora, Pocillopora, and Porites spp.), near the reef drop-off.
Carlson & Hoff (1993) described this attractive little discodorid from Guam and report that specimens have been collected from both Guam and Sarigan in the Northern Mariana Islands. The only other dark-spotted Okinawan discodorids having a superficial resemblance to H. brunneomaculata are Chromodoris aspersa and Halgerda onna. The resemblance of these two animals to H. brunneomaculata is superficial at best; the yellow ground color of the notum and the more dense appearing yellow-pigmented notal ridges of H. brunneomaculata provide no confusion in making field identifications with these animals.
The name brunneomaculata has reference to the dark brown spots present on the animal's mantle and body.