THE STEINHART AQUARIUM - Gulf of Guinea Science ...

CLASS HOLOTHUROIDEA
(SEA CUCUMBERS)
Yellow Sea Cucumber
Colochirus robustus (Cucumariidae)
Distribution: Indo-Pacific area, including
Indonesia and Philippines.
Habitat: It lives with its ventral surface in
contact with or buried in the sandy or rocky
substrate.
Appearance: A soft-bodied, bright yellow, 7 cm
elongated echinoderm with tube feet that cling
to the substrate. Like all echinoderms, it has
pentameral (five-rayed) symmetry. Five rows
of tube feet run from the mouth along the body.
Diet: A suspension feeder; on phytoplankton
and zooplankton; specialized mucouscovered
tube feet surround the mouth and
capture phytoplankton and zooplankton.
The animal then brings each foot to its mouth
systematically, essentially “licking its fingers.”
While other sea cucumbers are considered a
“sea floor janitors” because they “sweep” the
sand of food, the yellow is, by contrast, a filter
feeder.
Reproduction and Development: It spawns
annually in spring or summer. Its development
is either direct (lacks a larval stage) or
indirect (with a larval stage that undergoes a
metamorphic transition into a juvenile).
Mortality/Longevity: 5 to 10 years.
Remarks: An ability to release toxins keeps
away some predators.
The yellow sea cucumber is used in Chinese
and other Asian cuisines, most often as an
ingredient in soups or stews.
Several countries have imposed fishing
restrictions and have developed management
programs in the harvesting of these sea
creatures.
Philippine Sea Apple
Pseudocolochirus violaceus (Cucumariidae)
Distribution: Indian and west Pacific oceans;
India, Philippines and northern Australia.
Habitat: Relatively shallow reef flats.
Appearance: To 18 cm. Body and tentacles
can be various colors (violet, blue, red, yellow,
white) yet it always has yellow-red tube feet.
The most common body color is dark inky blue;
the tentacles are usually white.
California Academy of Sciences
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Diet: Filter feeds on plankton by extending
its oral tentacles into the current; as food is
trapped, it draws the tentacle into its mouth.
Reproduction and Development: Sexes
separate, fertilization external.
Mortality/Longevity: To 35 years.
Remarks: Venomous and considered to be
among the most toxic sea cucumbers in the
world: about 1 g of tissue from any of these
particularly toxic species could poison the fish
in a 95-liter tank. Toxins are released when the
animal is stressed or dies.
Creeping Pedal Sea Cucumber
Psolus chitinoides (Psolidae)
Distribution: North American Pacific coast
from the Aleutian Islands south to central Baja
California.
Habitat: Abundant in deeper water up to 245 m
on hard surfaces swept by currents. Somewhat
common in shallow subtidal areas preferring
clean, vertical rocks that are free of sediment.
Appearance: Beautifully colored bright orange,
oval in shape with 8–10 vividly colored red
branched tentacles extending out of the domed
dorsal surface. Upper body is covered with
large overlapping calcareous plates. Ventrally
the sole is flat and flexible with tube feet
extending around the perimeter and under the
length of the body, which are used to attach
firmly to the substrate. The mouth and anus are
located at opposite ends of the dorsal surface.
Typical size: 12 cm long/ 7.5 cm wide.
Diet: A suspension feeder, trapping particles of
food from currents with its tentacles. Feeding
occurs by extending the tentacles, bending
them inward to form a cage-like structure;
the mouth and lips extend toward the food as
the nearest tentacle pushes the food into the
mouth.
Reproduction and Development: Sexes
separate with spawning occurring annually
from mid-March to late May. Males disperse
sperm into the water column and fertilize the
eggs by waving a tentacle across the gonopore
of the females. Females release long strands
of red eggs. The fertilized eggs develop into
larvae nourished by stored lipids until the
juvenile stage when they settle on the substrate.
Mortality/Longevity: Preyed upon by several
species of sea stars, especially the leather sea