Opisthobranch of the Week Data
Dendrodoris nigra is considered to be common on Okinawa; I've collected eighteen specimens since the first one was collected in 1987. Numerous other have been seen but neither collected nor photographed. I think this is perhaps one of these axiomatic things found in the study and photography of wildlife; when something is commonly seen on a more or less regular basis it tends to be neglected, with the resultant absence of suitable specimens and photographs. This certainly is the case with myself concerning the above featured animal, as well as with several other commonly encountered Okinawan opisthobranchs. It would be nice to illustrate the huge variation seen in D. nigra as seen in the Okinawan material, much the same as Rudman (1999) has done with the Australian material on the Sea Slug Forum (see Bill Rudman's D. nigra page for an excellent presentation of this variably pigmented animal).
D. nigra is commonly found in many intertidal areas of tropical seas. On Okinawa it's more common to find D. nigra with a red ring around the perimeter of the notum, giving it quite a distinctive appearance. The above featured animal was found beneath a slab of coral rubble during a daytime low spring tide "reef walk".