THE STEINHART AQUARIUM - Gulf of Guinea Science ...

94 A Docent Field Guide to the Species of the Steinhart Aquarium
Blacktip Reef Shark
Carcharhinus melanopterus (Carcharhinidae)
Requiem Sharks
Distribution: Subtropical from Red Sea and East
Africa to the Hawaiian Islands and the Tuamoto
Archipelago. Also enters the Mediterranean from
the Red Sea (via the Suez Canal).
Habitat: Prefers inshore coral reefs and
the intertidal zone. Has been observed in
mangrove areas and fresh water, traveling in
and out with the tide.
Appearance: Up to 2 m long and weight up
to 13.6 kg. All fins tipped with black, the large
dorsal fin with a white band beneath the black
tip, conspicuous white bands along flanks,
sometimes edged with black. Otherwise,
yellowish-tan above, white below.
Diet: Mostly bony fish and cephalopods, also
other mollusks, shrimp.
Reproduction and Development: Viviparous,
incubate young for up to 16 months, 3– 4 pups
per litter. In a fashion not uncommon in sharks,
the male takes the female’s pectoral fin in his
teeth and the two mate belly to belly.
Mortality/Longevity: Preyed upon by other
sharks as well as large groupers. Average
lifespan c. 12 years.
Conservation Status: Listed as Near Threatened
by the IUCN, due to small litter size and long
gestation period.
Remarks: Often hunt in packs, driving prey
into a tight ball and then attacking the ball
in a feeding frenzy, even leaping out of the
water. Its distinctive appearance and active
swimming habit make it a favorite specimen
for aquariums. It has been known to bite people
wading in shallow water and is aggressive
towards spear fishers.
When foraging, may enter water so shallow that
both back and fins are exposed, a potentially
shocking sight to a wader.
Fortunately, there are very few reports of black
tips biting humans. Rare occurrences are most
likely a case of mistaken identity on the part of a
normally shy but easily frightened shark species.
Nearly all shark species are under heavy
pressure from an ever-more efficient fishing
industry. Blacktip populations are declining:
the flesh is eaten, the liver is prized for yielding
a valuable oil, and the fins are used for sharkfin
soup, especially in the Far East.
ORDER RAJIFORMES
(SKATES AND RAYS)
Bowmouth Guitarfish
Rhina ancylostoma (Rhinobatidae)
Guitarfishes
Distribution: Indo-West Pacific: Red Sea and
East Africa to Papua, New Guinea, north to
Japan, south to New South Wales, Australia.
Habitat: Sand and mud bottoms in coastal
areas, coral reefs close inshore. Sometimes
found in the water column. Found at depths
from 3–90 m.
Appearance: Length to 2.7 m, weight to 135 kg.
Broad, rounded snout, clearly demarcated from
the pectoral fin. Long tail. Gray or brownish
above, white below, white spots dorsally on fins,
body and tail, black spots on head and shoulders.
No venomous sting. Heavily ridged crushing
teeth. A large row of spines along the head, nape
and shoulders is a distinctive characteristic.
Reproduction and development: Ovoviviparous.
Diet: Primarily bottom-dwelling crustaceans
and mollusks.
Conservation Status: Vulnerable; not common,
population declining due to overfishing and
heavy pressure on habitat. A low reproductive
rate exacerbates its vulnerability.
Remarks: Although classified as a ray,
guitarfish do not have their pectoral fins fused
to their head as do other rays. In appearance
they look like a cross between a ray and a shark
and are often known as shovelnose sharks. In
most rays the caudal fins are separate from the
tail, but in guitarfish, again like sharks, the tail
is the caudal fin, though lacks a lower lobe.
They are caught for the Asian food market and
their pectoral fins are highly valued. When
caught in a net they are very difficult to handle
and can cause severe damage to other fish
caught at the same time.
The use for the spines is unknown; they may
be used for butting.
Big Skate
Raja binoculata (Rajidae)
Skates
Distribution: Bering Sea and southeastern
Alaska to central Baja California.
Habitat: Bottom dwellers on soft substrates,
usually from shallow water to 300 m. Found