young, red, 4.3 mm
blue marginal band
orange marginal band
with egg masses
Dendrodoris nigra (Stimpson, 1855)
|Maximum size: about 76 mm
species has a soft, gelatinous texture. In mature animals, the
notum is covered with
very small tubercles, arranged in clusters, with the central tubercle
in each cluster slightly larger. The body is usually black when mature
are typically bright orange-red and intermediate animals often have a black
margin and an orange-red submarginal band. Rarely, the orange-red band may be marginal rather than submarginal. (Note 1)
Also, some animals have a blue to blue-gray marginal band. Occasionally, mature
animals may be light brown with few or no darker blotches. The
tubercles and rhinophores are
usually tipped with white. The branchia are smaller, but more numerous,
than in Dendrodoris fumata.
is a common species found under rocks during the day or crawling in the
open at night from the low intertidal to 5 m (16 ft). It occurs at
moderately protected to moderately exposed rocky sites. We've found it
associated with a fine-textured, peach-colored sponge and
it may be eaten by the xanthid crab, Platypodia
eydouxi. (Note 2) It lays a yellow, spiral egg mass and the eggs hatch in about four days in the
Big Island, Maui, Oahu, Kauai, French Frigate Shoals, Midway and Kure (also Johnston Atoll): widely
in the Indo-Pacific.
species is referred to as the "black dendrodoris" in Hoover, 1998
It was first reported from Hawaii in Pease, 1860 (as Hexabranchus nebulosa). The drawing labelled Fig. 96d in Edmondson, 1946 is this species and Doridopsis Macfarlandi Ostergaard, 1955 is a synonym. (Kay, 1979) It's listed as Cryptodoris sp. in Ostergaard, 1950.
Photo: CP: 35
mm: Hekili Point, Maui; March 16, 2009.
Observations and comments:
1: In March, 2013 Daniel Jennings-Kam found an animal on the Big Island that had a marginal, rather than submarginal, orange-red band. (see photos). A marginal orange-red band is characteristic of the similar species, Dendrodoris arborescens. However, the form and color of the branchia, number of lamellae on the rhinophores and relatively slender profile suggest that it's probably a color form of D. nigra.
Note 2: On March 29, 2009 a student
reported finding a Platypodia
eydouxi holding a D. nigra
in its claw during a beach walk at Hekili Point, Maui. The animal was
somewhat mangled supporting the observation. This suggests that the
crab may prey on D.