Phyllidia varicosa Lamarck, 1801
|Maximum size: 102 mm.
longitudinal, blue-gray ridges composed of smooth, yellow-capped
tubercles. The ridges may be broken or continuous. Crescent-shaped,
blue-gray areas containing black spots and yellow-capped tubercles are
usually present around the mantle margin. The rhinophores are yellow. A
medial, black longitudinal stripe is present on the sole of the foot.
Occasional animals may have little or no yellow on the tubercles. It
may be distinguished from the less common Phyllidia
sp. #1 by the dark stripe on its foot and its dorsally located
anus. Young animals may sometimes lack the dark line. (Note 1)
is probably the nudibranch most frequently noticed by divers. It is a
species usually found in the open on rocks.
Occasionally, it may be seen crawling on sand in Halimeda kanaloana
beds (usually where some rubble is present) and it's the only phyllidiid
regularly found in that habitat. It occurs at moderately
protected to highly exposed locations at depths of 1-49 m (3-161 ft).
white egg ribbon and may feed on a cream sponge. (Note 2) Recent studies have
shown that its toxic secretions
may have anti-malarial properties. (Note 3) It may feed on the sponge, Ciocalypta sp. (Note 4)
Big Island, Maui, Lanai, Molokai, Oahu, Kauai and Niihau: widely distributed in
to the swollen, vein-like
ridges on the notum. In Hawaii, it is commonly referred to as the
"scrambled egg nudibranch" or the "fried egg nudibranch." It's also referred to as the "varicose
Phyllidia" in Hoover, 1998 & 2006. It was probably first reported from Hawaii in Edmondson, 1946 (as Phyllidia trilineata). (Note 5)
58 mm: Makena, Maui; July 5, 2008.
Observations and comments:
1: On Nov. 23, 1023, John Hoover reported that a young animal
(about 25 mm) lacked the dark line on its foot. However, other
characteristics (including the position of the anal papilla appear
comparable to this species (see photo).
Note 2: We've observed two individuals in
mating position three days in a row spanning at least 48 hours.
species in their mouth and spit it out immediately upon discovering its
chemical defense. Their tough bodies allow them to survive such
even when there is injury (see photo).
It's been reported in various studies of it's secretions as "feeding on the sponge Ciocalypta
sp." (a sponge with elongate, cream projections). However, photographic
evidence for that seems to be lacking on-line. What evidence does
appear on-line shows it associated with a massive white to cream sponge
but without obvious feeding damage...
Note 5: There's some chance that animals completely lacking yellow pigment (see photos) or with more isolated tubercles (see photo) might turn out to be distinct species.