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Additional Photos
in field
light
underside
texture
radula
copepods
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Pleurobranchella nicobarica
Thiele, 1925
Maximum size: about 220 mm.
Identification:
This
is
a
large, gelatinous species with a wrinkled surface and widely
scattered, small tubercles. Most animals are very dark brick-red
although a few may be light brown with white speckles on the tubercles.
The oral veil is tuberculate but lacks long sensory papillae.
Natural history:
At French Frigate
Shoals, fifteen animals were found in lobster pots baited with dead
herring suggesting that it's a scavenger. When held in buckets, some
displayed weak swimming motions. (Note 1) Most
were "infested" with commensal
copepods. (see photos) The
lobster
pots
were set over a depth range of 80-242 m
(262-794 ft) with
a minimum depth range for the animals of 128-178 m (420-584 ft). It
has also been
photographed by HURL submersibles at depths of 212-389 m (696-1276
ft). They
appear to excavate shallow pits in sand when resting.
Distribution:
Big Island, Oahu, Kahoolawe, Molokai, French Frigate Shoals, St.
Rogatien Bank, Raita Bank and Laysan: also known from Johnson Atoll.
Taxonomic notes:
It was first
recorded
in
Hawaii by the Undersea Research Laboratory (HURL)
during Makali'i submersible dive # M-65, principal investigator John
Wiltshire,
Jan 31, 1982.
Photo: CP:
dark form: 2006 CREEF
expedition; 150-163 m (492-535 ft); French Frigate Shoals; Oct. 13,
2006.
Observations and comments:
Note
1: Based on the display of swimming
motions when held and the number found in the baited traps, it's
tempting to speculate that they may find food by detecting the scent of
a dead fish and swimming up the scent trail to its source.
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