THE STEINHART AQUARIUM - Gulf of Guinea Science ...

mollusks except bivalves, is covered with
chitinous teeth which the white dorid uses to
scrape off its food.
Many species of nudibranchs are identified by
the structure of their radular teeth.
Terry Gosliner, Academy Senior Scientist,
is one of the world’s leading experts on
nudibranchs.
Sea Lemon
Peltodoris nobilis (Dorididae)
Dorid Nudibranchs
Distribution: Alaska to Baja California.
Habitat: Rocky areas, mostly at low intertidal
and subtidal depths to about 25m. Often seen
on harbor pilings.
Appearance: Color variable: may be pale
yellow to a deep rich yellow or orange. Back
is covered with tubercules and dark spots; gills
are white at the tips. One of the largest of all
nudibranchs; max. size: 20 cm.
Diet: Sponges.
Reproduction and Development: Hermaphrodites.
The coiled cream-colored egg ribbons,
each containing as many as 2 million eggs, are
sometimes seen in the exhibit.
Remarks: P. nobilis is one several dorid
nudibranchs with a fruity, distinct lemon scent
usually given off when the animal is handled,
thus its common name. When concentrated,
the odor repels many predators.
California is well-known for the diversity of
nudibranchs found in its coastal waters.
Opalescent Nudibranch
Hermissenda crassicornis (Fabelinidae)
Distribution: Kodiak Island, Alaska to Baja
California, Mexico; Japan
Habitat: Tidepools, rocks, pilings, mudflats.
Benthic: low tide line to 37 m.
Appearance: Length to 5 cm. Grayish white
body with neon blue edges, brilliant orange
dorsal pinstripe from front to back. Cerata
are burnt umber to brown with orange to
white tips.
Diet: Hydroids, sea anemones, sponges,
corals, bryozoans, other nudibranchs.
R e p r o d u c t i o n a n d D e v e l o p m e n t :
Hermaphroditic (possessing both male and
female organs), though rarely self-fertilizing.
Egg strings in narrow coils with as little as a
California Academy of Sciences
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few eggs to as many as a million. Eggs mature
in from five to 50 days depending on water
temperature.
Mortality/Longevity: Less than one year.
Remarks: An encounter between members
of this species may result in mutual mating
or hostile combat with the victor dining on
the loser.
One of several nudibranch species valued in
medical research for the study of ganglia and
nerves.
A good example of warning coloration; fish
have been observed to avoid this brightly
colored species whose nematocysts inflict
damage to the tissues of unwary consumers.
Adults store nematocysts, ingested from their
cnidarian prey, in the cerata.
California Sea Hare
Aplysia californica (Aplysiidae)
Distribution: Humboldt Bay, California to
Gulf of California.
Habitat: Among seaweed, sometimes in
kelp canopy, lower intertidal to over 18 m.
Occasionally in sandy areas, mudflats, bottom
of bays, estuaries and harbors.
Appearance: A huge (to more than 40 cm long
and weighing several kg) sea slug; reddish,
brownish and/or greenish (color dependent
on diet).
Diet: Herbivore. Feeds primarily diurnally on
various algae and the eelgrass Zostera.
Reproduction and Development: All adults
are simultaneous hermaphrodites. During
mating, any individual may perform as a male,
or as a female, or as both sexes simultaneously.
“Daisy chains” of mating animals are often
reported from the field. The designated female
lays long, tangled, yellow-green, spaghettilike
egg strings containing up to one million
eggs intertidally and subtidally among rocks
and algae. The eggs hatch ~two weeks later.
Hatched veliger larvae swim for ~one month,
settle and metamorphose into juveniles
which double their weight every 10 days for
3 months.
Mortality/Longevity: Very few species
have been reported as preying on postlarval
sea hares, possibly due to their toxic
digestive gland. Giant green anemones are