The term whale
is ambiguous: it can refer to all cetaceans
to just the larger ones, or only to members of particular families within the
. The last definition is the one followed here. Whales are
those cetaceans which are neither dolphins (i.e. members of the families
Delphinidae or Platanistoidea) nor porpoises. This can lead to some confusion
because Orcas ("Killer Whales") and Pilot whales have "whale" in their name, but
they are dolphins for the purpose of classification.
Humpback Whales Feeding off Cape Cod
Video, Movie, Film, Clip. Mpeg
Origins and taxonomy
All cetaceans, including whales, dolphins and porpoises, are descendants of
land-living mammals of the Artiodactyl order (even-toed ungulate animals). Both
cetaceaos and artiodactyl are now classified under the super-order
Cetartiodactyla which includes both whales and hippos. In fact, whales are the
closest living relatives of hippos; they evolved from a common ancestor at
around 54 million years ago.
Whales entered the water roughly 50 million years ago.
Cetaceans are divided into two suborders:
- The baleen whales are characterized by baleen, a sieve-like structure in the
upper jaw made of keratin, which they use to filter plankton from the water.
They are the largest species of whale.
- The toothed whales have teeth and prey on fish, squid, or both. An
outstanding ability of this group is to sense their surrounding environment
A complete up-to-date taxonomical listing of all cetacean species, including
all whales, is maintained at the Cetacea article.
Like all mammals, whales breathe air into lungs, are warm-blooded, feed their
young milk from mammary glands, and have some (although very little) hair.
The body is fusiform, resembling the streamlined form of a fish. The
forelimbs, also called flippers, are paddle-shaped. The end of the tail holds
the fluke, or tail fins, which provide propulsion by vertical movement. Although
whales generally do not possess hind limbs, some whales (such as sperm whales
and baleen whales) sometimes have rudimentary hind limbs; some even with feet
and digits. Most species of whale bear a fin on their backs known as a dorsal
Click Image to get better picture
|Baleen Whale Anatomy
Beneath the skin lies a layer of fat, the blubber. It serves as an energy
reservoir and also as insulation. Whales have a four-chambered heart. The neck
vertebrae are fused in most whales, which provides stability during swimming at
the expense of flexibility.
Whales breathe through blowholes, located on the top of the head so the
animal can remain submerged. Baleen whales have two; toothed whales have one.
The shapes of whales' spouts when exhaling after a dive, when seen from the
right angle, differ between species. Whales have a unique respiratory system
that lets them stay underwater for long periods of time without taking in
oxygen. Some whales, such as the Sperm Whale, can stay underwater for up to two
hours holding a single breath. The Blue Whale is the largest known mammal that
has ever lived, and the largest living animal, at up to 35 m (105ft) long and
Whales generally live for 40-200 years, depending on their species, but it is
rare to find one that lives over a century. Recently a fragment of a lance used
by commercial whalers in the 1800s has been found in a huge bowhead whale caught
off Alaska. The fragment showed the whale is estimated between 115 and 130 years
old.  "No other finding has been
this precise," said John Bockstoce, an adjunct curator of the New Bedford
Their skin has evolved hydrophilic properties. Its surface is covered with
microscopic pores surrounded by nanoridges.
Between these ridges there is a rubber-like gel
which is excreted from the gaps between the skin cells. This gel contains enzymes that attack microbes, and
the edge of the ridges makes it hard for smaller organisms to attach themselves.
Whale flukes often can be used as identifying markings, as is the case for
humpback whales. This is the method by which the publicized errant Humphrey the
whale was identified in three separate sightings.
|A Humpback Whale breaching
Anatomy of the ear
While there are direct similarities between the ears of whales and humans,
whales’ ears have specific adaptations to their underwater environment. In
humans, the middle ear works as an impedance matcher between the outside air’s
low-impedance and the cochlear fluid’s high-impedance. In aquatic mammals such
as whales, however, there is no great difference between the outer and inner
environments. Instead of sound passing through outer ear to middle ear, whales
receive sound through their lower jaw, where it passes through a low-impedance,
Whales are widely classed as predators, but their food ranges from
microscopic plankton to very large fish. Males are called bulls; females, cows.
The young are called calves.
Because of their environment (and unlike many animals), whales are conscious
breathers: they decide when to breathe. All mammals sleep, including whales, but
they cannot afford to fall into an unconscious state for too long, since they
need to be conscious in order to breathe. It is thought that only one hemisphere
of their brains sleeps at a time, so that whales are never completely asleep,
but still get the rest they need. Whales are thought to sleep around 8 hours a
Whales also communicate with each other using lyrical sounds. Being so large
and powerful these sounds are also extremely loud (depending on the species;
sperm whales have only been heard making clicks, as all toothed whales (Odontoceti)
use echolocation and can be heard for many miles. They have been known to
generate about 20,000 acoustic watts of sound at 163 decibels.
Females give birth to a single calf. Nursing time is long (more than one year
in many species), which is associated with a strong bond between mother and
young. In most whales reproductive maturity occurs late, typically at seven to
ten years. This mode of reproduction spawns few offspring, but provides each
with a high probability of survival in the wild.
The male genitals are retracted into cavities of the body during swimming, so
as to be streamlined and reduce drag. Most whales do not maintain fixed
partnerships during mating; in many species the females have several mates each
season. At birth the newborn is delivered tail-first, so the risk of drowning is
minimized. Whale mothers nurse the young by actively squirting milk into their
mouths, a milk that according to German naturalist Dieffenbach
, bears great similarities to cow's milk, except with a
much higher concentration of fat. Biologists compare the consistency of whale
milk to cottage cheese; it must be thick, or else it will dissipate into the
|Eighteenth century engraving of Dutch whalers hunting Bowhead
Whales in the Arctic. Beerenberg on Jan Mayen Land can be seen in the
Some species of large whales are endangered as a result of large-scale
whaling during the nineteenth and twentieth centuries. For centuries large
whales have been hunted for oil, meat, baleen and ambergris (a perfume
ingredient from the intestine of sperm whales). By the middle of the 20th
century, whaling left many populations severely depleted.
The International Whaling Commission introduced a six year moratorium on all
commercial whaling in 1986, the moratorium was due to be lifted in 1992 but has
been extended till the present day. For various reasons some exceptions to this
moratorium exist; current whaling nations are Norway, Iceland and Japan and the
aboriginal communities of Siberia, Alaska and northern Canada. For details, see
Several species of small whales are caught as bycatch in fisheries for other
species. In the tuna fishery in the Eastern Tropical Pacific thousands of
dolphins were drowned in purse-seine nets, until measures to prevent this were
introduced. Fishing gear and deployment modifications, and eco-labelling (dolphin-safe
or dolphin-friendly brands of canned tuna), have contributed to an
estimated 96% reduction in the mortality of dolphins by tuna fishing vessels in
recent years. In many countries, small whales are still hunted for
food, oil, meat or bait.
Environmentalists have long argued that some cetaceans, including whales, are
endangered by sonar used by advanced navies. In 2003 British and Spanish
scientists suggested in Nature that sonar is connected to whale beachings
and to signs that the beached whales have experienced decompression sickness.
 Mass whale beachings occur in many
species, mostly beaked whales that use echolocation systems for deep diving. The
frequency and size of beachings around the world, recorded over the last 1,000
years in religious tracts and more recently in scientific surveys, has been used
to estimate the changing population size of various whale species by assuming
that the proportion of the total whale population beaching in any one year is
Despite the concerns raised about sonar which may invalidate this assumption,
this population estimate technique is still popular today. Researchers in the
area (Talpalar & Grossman, 2005) support the view that it is the combination of
the high pressure environment of deep-diving with the disturbing effect of the
sonar which causes decompression sickness and stranding of whales. Thus, an
exaggerated startle response occurring during deep diving may alter orientation
cues and produce rapid ascent.
Following public concern, the U.S. Defense department has been ordered by the
U.S. judiciary to strictly limit use of its Low Frequency Active Sonar during
peacetime. Attempts by the UK-based Whale and Dolphin Conservation Society to
obtain a public inquiry into the possible dangers of the Royal Navy's equivalent
(the "2087" sonar launched in December 2004) have so far failed. The European
Parliament on the other hand has requested that EU members refrain from using
the powerful sonar system until an environmental impact study has been carried
|Northern Bottlenose whale - 8-15m in length
On 20 January
2006, a Northern Bottlenose Whale was spotted in Central London in the River
Thames. The River Thames whale reached as far up river as Albert Bridge. It was
moved onto a barge and rescuers hoped to take it out to sea, but it died
following a convulsion on 21 January during its rescue. Its skeleton is now in
the Natural History Museum in London.
Other environmental disturbances
Conservationists are concerned that seismic testing used for oil and gas
exploration may also damage the hearing and echolocation capabilities of whales.
They also suggest that disturbances in magnetic fields caused by the testing may
also be responsible for beaching. 
Some scientists and environmentalists suggest that some whale species are
also endangered due to a number of other human activities such as the
unregulated use of fishing gear, that often catch anything that swims into them,
collisions with ships, toxins and the combination of toxins POPs among other
Whales are also threatened by climate change and global warming. As the
Antarctic Ocean warms, krill populations, that are the main food source of some
species of whales, reduce dramatically, being replaced by jelly like salps.
Whales in culture
- A kenning in Beowulf refers to the sea as the "whale-road".
- Procopius mentions a whale, nicknamed Porphyrio by the Byzantines,
who depleted fisheries in the Sea of Marmara.
- The King James Version of the Bible mentions whales four times: "And God
created great whales" (Genesis 1:21); "Am I a sea, or a whale, that thou settest
a watch over me? (Job 7:12); "Thou art like a young lion of the nations, and
thou art as a whale in the seas (Ezekiel 32:2); and "For as Jonas [sic] was
three days and three nights in the whale's belly; so shall the Son of man be
three days and three nights in the heart of the earth" (Matthew 12:40).
- Nevertheless, the passages in question do not unambiguously refer to whales;
modern translations tend to use other terms; for example the New International
Version uses "creatures of the sea"; "monster of the deep"; "monster"; and "huge
- The story of Jonah being swallowed by a whale is mentioned in the Qur'an as
- A whaling voyage is the plot of Herman Melville's novel Moby-Dick. In
the book, Melville classed whales as "a spouting fish with a horizontal tail",
this despite science suggesting otherwise the previous century. (His narrator
acknowledged "the grounds upon which Linnaeus would fain have banished the
whales from the waters" but writes that when he presented them to "my friends
Simeon Macey and Charley Coffin, of Nantucket ... they united in the opinion
that the reasons set forth were altogether insufficient. Charley profanely
hinted they were humbug" (Chapter 32).) Melville's book is a classic of American
literature: part adventure novel, part metaphysical allegory, and part natural
history; it is essentially a summary of 19th century knowledge about the
biology, ecology and cultural significance of the whale.
- Some cultures associate some level of divinity with the whale, such as in
some places in Ghana and the Vietnamese, who occasionally hold funerals for
beached whales, a throwback to Vietnam's ancient sea-based Austro-Asiatic
- Festivals celebrating whales have sprung in both Sitka and Kodiak Alaska.
They feature speakers on marine biology and celebrate the creatures with art,
music, whale watching cruises, and symposiums.
- In the British series Hitchhiker's Guide to the Galaxy a Whale, alongside a
bowl of Petunias, is created upon the usage of the Infinite Improbability Drive
|Ginkgo-toothed Beaked Whale - Can reach up to 4.9 m in length
What those Japanese whale fleets are doing