Page 420 - (DK) Ocean - The Definitive Visual Guide

418 ANIMAL LIFE

ORDER CETACEA There are two species of pilot whales, squid and octopus. They are highly
distinguished primarily by the length gregarious, living in groups that can STRANDING
Long-finned of their flippers—a feature that is be hundreds strong, and often associate
difficult to observe at sea. The with other cetaceans. They easily Pilot whales often become
Pilot Whale long-finned pilot whale lives mainly become disoriented in shallow coastal stranded on beaches. If one whale
in cold-water regions. It has glossy, waters, often becoming stranded in strands, others frequently follow,
Globicephala melas
jet black coloration, with an anchor- large numbers. This tendency to herd leading to a mass stranding.
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LENGTH 11 / 2 –23 ft shaped pale patch on the throat and together has been exploited for Theories to explain stranding
(3.5–7 m)
chest. This species has a bulbous head centuries by whale hunters, who were involve factors that disrupt the
WEIGHT Up to 3.8 tons and short jaws. Its long dorsal fin has able to drive them into shallow water whales’ navigational systems, such
(3.5 metric tons)
a hooked shape in males. Its flippers for slaughter. In some locations—such as temporary anomalies in Earth’s
HABITAT Cold coastal have a sharp backward bend, or as the Faroe Islands—pilot whales are magnetic field, ships’ sonar,
waters, open oceans
“elbow,” and are up to a fifth of its still hunted today. sickness, and storms.
DISTRIBUTION Temperate and subpolar waters body length. Long-finned pilot
worldwide, except north Pacific
whales feed mainly on deep-water

ORDER SIRENIA
West African
Manatee

Trichechus senegalensis
LENGTH 10–13 ft (3–4 m)
WEIGHT Up to 1,100 lb
(500 kg)
HABITAT Mangrove
swamps, lagoons, inland
waterways, estuaries
DISTRIBUTION West Africa, from Senegal to Angola

One of three species of manatees, this
docile vegetarian lives mainly in fresh
water but also feeds in the mangrove
swamps on Africa’s west coast. It has
a barrel-shaped body covered in
coarse gray skin and front flippers
with tiny nails. Like all sirenians,
it has no hind limbs and swims
with its spoon-shaped tail, which
ORDER CETACEA swims into rivers. It has a short, barrel- slowly beats up and down as it
like body, with small flippers and a cruises through the shallows.
Harbor Porpoise blunt dorsal fin. Its overall color is Using its fleshy lips, it feeds
dark gray, while its underside is paler. on plants above and below the
Phocoena phocoena Unlike most dolphins, this porpoise water line. Manatees lack the
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LENGTH 4 / 2 –6 / 2 ft has a blunt snout, which houses 21–28 complex stomachs of terrestrial
(1.4–2 m) pairs of spade-shaped teeth in each plant-eaters such as cattle and
WEIGHT Up to 145 lb jaw. Harbor porpoises often live alone, antelopes. Most digestion
(65 kg) or sometimes in pairs or small groups; occurs in their intestines,
HABITAT Coastal waters, they feed on fish and shellfish. which may be 150 ft (45 m)
OCEAN LIFE in Northern Hemisphere single calf is tiny by cetacean standards, and give birth to young
tidal regions of rivers
long. West African manatees
Females give birth after a gestation
period of up to 11 months, and the
live in groups of up to six
DISTRIBUTION Cold-temperate and subpolar waters
about 3 ft (1 m) long. Their
weighing as little as 13 lb (6 kg). In
One of the most common cetaceans
slow reproductive rate
the past, harbor porpoises were often
in the Northern Hemisphere, the
makes them vulnerable
hunted for meat and as a source of
harbor porpoise, as its name suggests,
oil. Today, a greater threat is posed by
to environmental change,
rarely strays into deep water. It prefers
and to hunters who target
fishing nets—being small, it is easy for
shallow, coastal waters and sometimes
them to become accidentally trapped.
them for meat and skin.