young, 5 mm
mating & egg mass
|Maximum size: 80 mm.
is a flattened sea hare with parapodia closely appressed to the
body and two small apertures on the posterior portion. The rhinophores
and cephalic tentacles are small and it is variously mottled in brown,
red and olive green. Occasionally, it may be uniform brown or reticulated. There are short, sometimes branching, papillae on
the notum. (Note 1)
is a common species found in the low intertidal and tide pools in rocky
areas. It occurs at protected to exposed locations. Occasionally, it
may be found subtidally to depths of 9 m (30 ft), usually at more
windward sites. It's a nocturnal sea hare that lays egg masses composed
of a flattened egg string attached to the bottom of a rock in a
tight, zig-zag pattern. (Note 2)
Big Island, Maui, Molokai, Oahu, Kauai, Niihau, French Frigate Shoals,
Pearl & Hermes Reef and Midway (also Johnston Atoll): widespread in the Indo-Pacific.
shell drawing in Kay, 1979 is probably of a juvenile shell from Phyllaplysia cf. lafonti, instead of this
species. It's referred to as the "common sea hare" in Hoover, 1998
& 2006. It was probably first reported from Hawaii in Eydoux & Souleyet, 1852 (as Aplysia oahuensis). Dolabrifera olivacea
Pease, 1860 is a synonym (Kay, 1979) and it is listed in Edmondson,
1946 and Ostaargard, 1950 under that name. There's a chance that subtidal animals with more
elaborate papillae, the brown form and/or the reticulated form could prove to be distinct. (Note 3)
mm: Ulua Beach, Maui; March 31, 2006.
Observations and comments:
1: The less common subtidal animals
seem to have more elaborately branched papillae, on average. (see photo).
The eye spots in this species appear to be at the bottom of shallow,
concave depressions that variably reflect blue light. Perhaps, the
depressions reflect more blue/UV light onto the spots increasing their
ability to detect light intensity/direction at night?
Note 3: The brown form has been observed clustering with "normal" animals.