Hypselodoris maridadilus Rudman, 1977
|Maximum size: 34 mm (Bertsch
and Johnson, 1981); about 50 mm for flecked animal.
species has a bright-white body with five longitudinal purple-pink
lines on the notum and a purple-pink line on the margin of the mantle.
The rhinophores are orange with tiny white tips and the gills are
orange with white on the upper edges. Some animals may have flecks between the lines.
is a moderately rare species in the main islands but is commonly seen
Midway Atoll. It is found in moderately protected locations on rocky
bottoms and patch reefs at depths of < 1 to 20 m (< 3 to 65 ft).
lays an orange egg mass.
Maui, Oahu, Lisianski and Midway: widely distributed in the Indo-Pacific.
authors consider the Hawaiian population to be Hypselodoris whitei (Adams &
1850) rather than H.
maridadilus (restricting the latter to the Indian Ocean). See
the See Slug
Forum for further discussion. Described from East Africa, its
scientific name comes
from the Swahili
word "maridadi" which means "beautiful." It's referred to as the
"magenta-striped nudibranch" in Hoover, 1998 & 2006. It was
probably first reported from Hawaii in Eydoux and Souleyet, 1852 (as Doris lineata). (Note 1)
Photo: PF: 29
mm: Napili Bay, Maui; Aug. 19, 1994.
Observations and comments:
1: The only photo we've seen with a lighter color and flecks
between the lines was from Midway. (see photo) However, the photo of H. maridadilus
in Gosliner, et. al. (2018) shows a typical color pattern and is also
from Midway. Whether the flecked form is restricted to Midway or we just
haven't found it elsewhere due to the small sample size is unknown.
There's some possibility that it could be distinct but rhinophore color,
branchia color and the basic pattern of the lines are the same. That
argues for lumping (pending DNA work...). Or, perhaps the flecks develop
with age since the recent Midway animal was very large for the species?