THE STEINHART AQUARIUM - Gulf of Guinea Science ...

only differences in light and dark.
Blood stars lack pedicellariae (tiny pincers for
removing ectoparasites and debris, common
to most sea stars).
Leather Sea Star
Dermasterias imbricata (Poraniidae)
Distribution: Eastern North Pacific: Alaska to
Northern California.
Habitat: On rocks and rocky reefs in subtidal
areas.
Appearance: Medium size sea star up to 12
cm in diameter with disproportionately short
arms. Mottled coloring—bluish-grey with
brown to orange blotches all over.
Diet: Mainly sea anemones, but also takes
sea cucumbers, sea urchins, and other invertebrates.
Reproduction and Development: Releases
eggs and sperm; fertilized eggs float in plankton
and develop into juveniles, which eventually
settle out.
Remarks: Is smooth and slimy to the touch;
smells like garlic. Leather stars, unlike many
other sea stars, such as the ochre, bat, and
pink sea stars, swallow their prey whole and
digest internally.
Pink Sea Star aka Pink Pisaster
Pisaster brevispinus (Asteriidae)
Distribution: Sitka, Alaska to San Diego
County, California.
Habitat: Occasional in low intertidal zone,
more common 0.5–100 m on sand and mud
substrates, sometimes on rocks and pier pilings
in calm waters.
Appearance: Maximum diameter nearly 1 m,
individuals usually smaller. Pink color diagnostic.
Robust appearance. Aboral spines much
shorter than those of other Pisaster species.
Diet: Preys on live clams, snails, sand dollars,
barnacles, mussels, tube-dwelling annelid
worms, and scavenges dead fish and squid.
Reproduction and Development: Spawns in
the spring.
Mortality/Longevity: Likely preyed upon by
the sunflower sea star Pycnopodia helianthoides.
Remarks: Can chemosense clams through
sand. May dig down to the clam for 2 –3 days
or extend tube feet to the clam a distance equal
to the arm radius (to 20 cm!) Once contacted,
California Academy of Sciences
87
the clam is lifted from the substrate or the
stomach may be everted to 8 cm to digest the
prey in place.
Some sand-bottom invertebrates including
the sand dollar Dendraster excentricus and
the snail Olivella biplicata chemosense the
presence of a pink star and attempt to avoid
contact by burrowing.
Giant Sea Star
Pisaster giganteus (Asteriidae)
Distribution: Eastern Pacific coast from
British Columbia to Baja California.
Habitat: Rocky but also sandy substrates from
middle to lower intertidal zone down to 90 m.
Appearance: Five arms. Can be colored red,
orange, brown, or green. Evenly spaced blunt
spines. Maximum arm span about 60 cm.
Diet: Typical prey are hard-shelled organisms
such as mussels, snails, and barnacles. May
occasionally eat anything slow-moving
enough to be caught, such as dying fish or
shellfish, anenomes, or other sea stars.
Reproduction & Development: Individual
sea stars are male or female. Both sexes
release gametes into the water for external
fertilization. Larvae are planktonic and have
bilateral symmetry.
Mortality/Longevity: Sea gulls and sea otters
are sea star predators. Giant sea stars live about
20 years.
Ochre Sea Star aka Pacific Sea Star
Pisaster ochraceus (Asteriidae)
Distribution: Prince William Sound, Alaska to
Santa Barbara County, California.
Habitat: Low-middle intertidal zones on rocky
shores, especially on mussel beds. Subtidal to 88
m depth. Juveniles in crevices and under rocks.
Appearance: Arm radius to 28 cm (usually half
that figure). Rays 5–7, typically 5. Colored orange,
violet, green and mottled; very rarely ochre.
Diet: California mussels (Mytilus californianus)
are the favored and locally abundant prey.
Also consume acorn barnacles, emarginate
dogwinkles, gooseneck barnacles, owl limpets,
etc. Can insert stomach into slits as narrow as
0.1 mm between the valves of bivalves and
begin digestion.
Reproduction and Development: Sexual reproduction
occurs during the spring. Mature