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Additional Photos

underside

pale

isolated tubercles

feeding

injured

regeneration error?

mating

laying eggs
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GALLERY

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Phyllidia varicosa Lamarck, 1801

Maximum size: 102 mm.
Identification:
This
well-known
species
is
elongate-oval
with
three
to six
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.
Natural history:
Phyllidia varicosa
is probably the nudibranch most frequently noticed by divers. It is a
common
species usually found in the open on rocks, sometimes feeding on the
sponge Ciocalypta sp.
Occasionally, it may be seen crawling on sand in Halimeda kanaloana
beds (usually where some rubble is present) and is
the only phyllidiid found in that habitat. It occurs at moderately
protected to highly exposed locations at depths of 1-49 m (3-161 ft).
It lays
a flat
white egg ribbon. (Note 1) Recent studies have
shown that its toxic secretions
may have anti-malarial properties. (Note 2)
Distribution:
Big Island, Maui, Lanai, Oahu, Kauai and Niihau: widely distributed in
the
Indo-Pacific.
Taxonomic notes:
The
name
means
"dilated
veins"
in
reference
to the swollen, vein-like
ridges on the notum. In Hawaii, it is commonly referred to as the
"scrambled egg nudibranch" and is referred to as the "varicose
Phyllidia" in Hoover, 1998 & 2006.
Photo: PF:
58 mm: Makena, Maui; July 5, 2008.
Observations and comments:
Note
1: We've observed two individuals in
mating position three days in a row spanning at least 48 hours.
Note 2:
We've
observed
fish,
such
as
the
jack
Caranx melampygus,
take this
species in their mouth and spit it out immediately upon discovering its
chemical defense. Their tough bodies allow them to survive such
attacks,
even when there is injury (see photo).
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