In the Marshalls, Dendrodoris nigra adults are almost always black, with or without a varying number of small white spots. However, like Dendrodoris fumata, D. nigra can be variable in color in some areas. Coloration of the two species may at times overlap. One feature that differentiate them is said to be the size of the gills. In D. fumata, the gills are large and cover much of the animal's width near the posterior end. In D. nigra, the gills are generally just a small cluster of branchiae roughly in the shape of a ball. This species is relatively common under rocks in shallow water. We have found it at Enewetak, Kwajalein, Bikini, and Ujelang Atolls, generally under dead coral at depths less than 10 meters. It has also been observed at Rongelap Atoll by John and Lynette Flynn. The animal immediately below was photographed at Kwajalein Atoll on 11 February 2008. These were first reported from the Marshalls from Enewetak Atoll by Marcus & Burch (1965). This species is also common on shallow reefs in Hawaii.
The adult below has just deposited an egg mass.
Juvenile Dendrodoris nigra are often bright red in color.
The next series of three photos by John and Lynette Flynn show some extreme variations found along shallow reefs at Rongelap Atoll, Marshall Islands. The specimens ranged from mostly smooth but heavily spotted with white to solid black and very bumpy. The differences make one wonder if there might be multiple cryptic species hiding behind the Dendrodoris nigra name.
Here are a couple of fairly heavily speckled individuals at Kwajalein, the first from 22 November 2010.
Sometimes the adults retain a bit of the juvenile red coloration.
In late June 2010, there were lots of small brown juveniles around.
Created 28 December 2006
Updated 3 May 2021