THE STEINHART AQUARIUM - Gulf of Guinea Science ...

62 A Docent Field Guide to the Species of the Steinhart Aquarium
in sacs located between the gills, mixed with
mucus, and spread through the water by a jet
of water from the funnel.
Recent studies have shown that cephalopod
ink is toxic to some cells, including cancer cells.
Dwarf Cuttlefish
Sepia bandensis (Sepiidae)
Cuttlefish
Distribution: The Indo-Pacific region,
including the Philippines, Indonesia, and
Papua New Guinea.
Habitat: Shallow coastal waters near or on
coral reefs or sandy substrates.
Appearance: Length: 5 cm–10 cm. It has 8 arms
with rows of suckers along each and 2 feeding
tentacles. The animal moves by the undulation
of lateral fins that surround the body.
Diet: Crustaceans and fish. The feeding
tentacles shoot out to capture prey with suckers
and , along with arms and a parrot-like beak,
hold the prize while the cuttlefish radula
scrapes off digestible parts. Active diurnally.
Reproduction and Development: They mate
at 2–4 months of age, a time when the male
changes colors to black and white and displays
aggressive behavior to other males. Viable eggs
may take up to a month to hatch.
Mortality/Longevity: Life span: 6 mos. to 3 yrs.
Remarks: The cuttlefish isn’t a fish at all–it
is a cephalopod, closely related to octopuses,
squid, and nautiluses.
Cuttlefish have an internal shell within their
bodies that they can fill with more or less gas
to create neutral buoyancy. Cuttlebone is often
collected and used as a calcium supplement,
beak sharpener, and all-purpose toy for caged
birds.
Like most cephalopods, cuttlefish have 3
hearts. Two hearts pump blood to the gills,
and a central heart pumps oxygenated blood
to the body.
Masters of camouflage, cuttlefish and most
cephalopods can change their colors, shapes
and textures in seconds to avoid predators and
blend into their surroundings. They have keen
vision, but are color blind.
They also produce large amounts of ink, both
as a decoy and foul-tasting deterrent. Known
as sepia ink, after the genus name of cuttlefish,
it was a dye once prized by artists.
The Steinhart Aquarium is the first institution
in the U.S. to breed dwarf cuttlefish. To date,
(2010) more than 350 have hatched at the
Academy, most of which have been sent to
other aquaria and research institutions.
Quote from Rich Ross, Academy biologist and
cuttlefish breeder extraordinaire: Over time,
[cuttlefish] learn to recognize and respond to
you, and will often greet you when you walk
into the room (or maybe they just know you
bring the food). They are smart, beautiful and
unusual, and unlike certain other eight-armed
cephalopods (think octopus), they don’t try to
escape from your aquarium!
Giant Pacific Octopus
Enteroctopus dofleini (Octopodidae)
Distribution: Range throughout temperate
Pacific waters, from southern California north
to Alaska, west to the Aleutian Islands and
Japan.
Habitat: Occur in intertidal zones and to
depths up to 750 m.
Appearance: Large bulbous “head” (mantle)
with 8 tentacles bearing suckers. Very large
specimens can have a tentacle span of more
than 9 m from tip to tip, and weigh more than
45 kg.
Diet: Mostly crustaceans (shrimps, crabs,
scallops,) and mollusks (abalones, clams); fish
and other octopuses are also eaten. Shells of
prey that are difficult to pull or bite open can
be “drilled” in order to gain access to the soft
tissue: salivary secretions soften the shell, and a
tiny hole is created with the radula (a toothed,
hardened “tongue”). The octopus then secretes
a toxin that paralyzes the prey and begins to
dissolve it. The shell is pulled apart and the
soft tissues are consumed.
Reproduction and Development: Males
appear to be drawn to the female by following
a scent she releases into the currents. The
third right arm of the male has a modified tip
that is used during mating to transfer large
spermatophores (up to 1 m long) to the female,
which she accepts from one or more males,
and stores for future use. It may take several
weeks for the female to find a suitable den for
her eggs. She lays the 20,000 to 100,000 eggs,
fertilizing each as it is produced. She tends,
cleans, and aerates them until they hatch 5–7
months later (rate of development depends