THE STEINHART AQUARIUM - Gulf of Guinea Science ...

56 A Docent Field Guide to the Species of the Steinhart Aquarium
Habitat: Low intertidal zone to sub-intertidal
to about 20 m depth.
Appearance: A large marine gastropod.
Circular shell with undulating (“wavy”)
ridges. Max. size: 13 cm.
Diet: Algae.
Remarks: The shell is often covered with algae
and other encrusting organism, an effective
means of camouflage.
Queen Conch
Strombus gigas (Strombidae)
Distribution: South Florida, Bahamas and
Caribbean.
Habitat: Sea grass beds (especially turtle grass
Thalassia testudinum), sand flats and shallow,
sandy lagoons, often around patch reefs.
Appearance: Short conical spire with blunt
spikes. Shell’s exterior is orangish, often obscured
by algal growth and debris. Aperture
rosy-pink, with a thickened flared lip. Mottled
gray head with large proboscis and long eye
stalks. Eye at tip of stalk, tentacles below. Long,
claw-like operculum.
Diet: Primarily microscopic algae grazed from
the surface of the blades of turtle grass.
Reproduction and Development: Mating occurs
in open sandy areas, the two partners lined
up fore to aft. Packets consisting of gelatinous
strings of eggs are deposited on sandy substrates.
Eggs hatch into planktonic larvae. Adult
reaches 30 cm length in 2–3 years. After that time
shell is thickened by additional layers of calcium
carbonate added on the internal surface.
Mortality/Longevity: Juveniles preyed
upon by gastropod mollusks, cephalopods,
crustaceans and fishes. Adults are consumed
by sharks and loggerhead turtles; the latter is
capable of crushing the shells of adult queen
conchs. Avidly preyed upon by humans as a
food source.
Conservation Status: Has become uncommon
in many locations, especially in shallow depths,
due to overharvesting for food.
Remarks: Locomote by hopping by extending
the muscular foot and “pole vaulting.” Adults
can move vertically with waving motions of the
foot and also adhere to substrates.
The conchfish (Astrapogon stellatus) spends
daylight within the mantle cavity of this conch,
and emerges nocturnally to feed.
A conch pearl is formed when an animal or
mineral particle trapped beneath the mantle is
covered with layers of calcium carbonate until
it reaches nearly marble-size.
Marble Cone Snail
Conus marmoreus (Conidae)
Distribution: Red Sea, Indo-Pacific.
Habitat: Shallow water to 90 m depth.
Appearance: Shell length to 10 cm. Flat,
noduled spire. Reticulated pattern of black or
dark brown with white patches overall.
Diet: A predator of predators; harpoons on
other members of its family (Conidae). Its
“harpoon” is a single, specialized radula tooth
equipped with a spearlike barbed tip. The
barbed tooth has a groove through which the
snail injects a neurotoxic peptide poison into
its victim.
Remarks: Research on cone snail toxins is an
active field and has resulted in a new highly
effective painkiller recently approved by the
FDA that, unlike opium-derived medications,
has a low risk of addiction.
Small cone snails pose little danger to humans
beyond a beelike sting; however, large cone
snails inject enough toxin to be deadly. About
30 human deaths have been attributed to cone
snail envenomation.
SUBCLASS OPISTHOBRANCHIA
(SEA SLUGS AND THEIR KIN)
White Dorid
Doris odhneri (Dorididae)
Distribution: Alaska to California.
Habitat: Rocky areas, mostly at low intertidal
and subtidal depths.
Diet: Sponges.
Appearance: Body of uniform color, usually
white. Like all dorid nudibranchs, the
rhinophores and gills are retractable into
pockets on the mantle. Tubercles on the mantle
are especially large around the animal’s
rhinophores and gill bush to protect these
structures. Max. length: 20 cm.
Remarks: Dorids have radulae with smooth,
hook-like teeth characteristic of the family.
The radula, a file-like organ possessed by all