Page 342 - (DK) Ocean - The Definitive Visual Guide

340 ANIMAL LIFE

ORDER COELACANTHIFORMES lobe in the middle, and its body is DISCOVERY ORDER COELACANTHIFORMES
covered in heavy scales, which are
Coelacanth made up of four layers of bone and FOSSIL EVIDENCE Indonesian
a hard mineral material. In life, these
Latimeria chalumnae shimmer an iridescent blue with Coelacanths were thought to have Coelacanth
LENGTH Up to 6 ft (2 m) white flecks. Coelacanths live in deep become extinct about 65 million
water on steep, rocky reefs and, so far, Latimeria menadoensis
WEIGHT Up to 210 lb years ago. When a live coelacanth
1
(95 kg) have been found at only a few sites off was caught in 1938, comparing LENGTH Up to 4 / 2 ft
(1.4 m)
the south and east coasts of Africa and
DEPTH 490–2,300 ft it with fossil coelacanths enabled
(150–700 m) the west coast of Madagascar. By using scientists to confirm its identity. A WEIGHT Up to 200 lb
(90 kg)
small submersibles to study these fish, living specimen of a fossil group
DISTRIBUTION Western Indian Ocean scientists have discovered that they had been found. DEPTH 490–655 ft
(150–200 m)
retreat into caves at night. When out
When it was first discovered in 1938, searching for food, they drift along in DISTRIBUTION Celebes Sea, north of Sulawesi,
in the western Pacific
the coelacanth was nicknamed “old ocean currents or scull slowly with
four legs” because its pectoral fins had their fins. Having located a fish or
strange, fleshy, limblike bases. The squid, the coelacanth then uses its When the Indonesian coelacanth
only other primitive group to have a powerful tail to propel itself forward was discovered in 1998, it was at
similar arrangement are the freshwater so that it can seize its prey. The first thought to be the same species
lungfish. It is from fish like these that coelacanth is listed as Critically as the one found in African waters
the first four-legged land animals are Endangered on the IUCN Red List (see left). The two are indeed very
thought to have developed. This of Endangered Species. International FOSSIL COELACANTH similar, but molecular studies suggest
coelacanth’s tail has an extra small trade in this species is banned. Fossil specimens of coelacanths have features that they are different species. An entire
almost identical to present-day coelacanths, ocean separates them, and because
including the unique coelacanths are slow swimmers, the
three-lobed tail. populations are not thought to mix.
The Indonesian coelacanth has the
same white markings and distinctive
gold flecks as the African species, but
it is brown rather than bluish. As yet,
little is known of its life history, but
because it is so physically similar to
the African species, it probably has the
same behavior and could therefore be
endangered by fishing.

ORDER ACIPENSERIFORMES HUMAN IMPACT
European Sturgeon CAVIAR BAN

Once common, the European
Acipenser sturio
LENGTH 11 ft (3.5 m) sturgeon is now extremely rare
WEIGHT Up to due to overfishing and poaching,
880 lb (400 kg) and because locks and polluted
DEPTH 13–295 ft estuaries have made many rivers
(4–90 m) unsuitable for spawning. Few
active spawning sites remain. This
DISTRIBUTION Coastal waters of northeastern sturgeon is critically endangered,
Atlantic, Mediterranean, and Black Sea and international trade in
the fish itself and any
Like most sturgeon, this species products from it,
swims from the sea into large rivers including caviar ORDER ACIPENSERIFORMES The beluga is both the largest species
to spawn in gravelly areas. These (salted roe), has of sturgeon and the largest European
prehistoric-looking fish belong to been banned. Beluga Sturgeon fish to enter fresh water. Stouter and
a primitive group in which only the heavier than the European sturgeon
skull and some fin supports are made Huso huso (see left), it has a more triangular
of bone. The rest of the skeleton LENGTH 16 ft (5 m) snout with a very wide mouth. Four
consists mainly of cartilage. Instead the pointed snout and are used to long barbels hang from the underside
WEIGHT Up to 4,400 lb
of scales, five rows of distinctive bony search out bottom-living invertebrates. (2,000 kg) of the snout, reaching almost to the
plates, or scutes, run along the body. The European sturgeon is thought to DEPTH 230–590 ft mouth. Like all sturgeon, the beluga
OCEAN LIFE barbels flattened, bony head bony scute DISTRIBUTION Northern Mediterranean, Black Sea, large upper lobe. Reputed to be the
live for at least 60 years.
Two pairs of barbels hang down from
has an asymmetrical, sharklike tail
(70–180 m)
with the backbone extending into the
most expensive fish in the world, it
Caspian Sea, and associated rivers
also produces the most prized caviar,
with large fish containing 220–440 lb
(100–200 kg). The beluga sturgeon is
endangered due to poaching and
damming of its spawning rivers.