The biggest of all animals, Whales are divided into two suborders:
Mysticeti meaning Baleen Whales and Odontoceti or Toothed Whales.
Baleen Whales are larger and have a baleen, a sieve like structure that
filters the small fish that they consume, from water. Toothed Whales
have teeth that they use to consume fish and squid. They are also known
for their ability to emit sounds and use them to navigate and forage, a
phenomenon known as Echolocation. Whales produce the loudest sounds
amongst animals and often vocalize songs that may last for as long as
half an hour, possibly to communicate, track offsprings, locate prey or
attract mates.
Extremely large and strong, Whales have no
natural threats. They may weigh up to one hundred and fifty to two
hundred tons. Body length often exceeds one hundred feet. Physique is
fusiform and streamlined, allowing it to swim freely. Vertebrae of neck
are joined together, providing stability in movement. Heart is four
chambered and body temperature is regulated like all warm blooded
mammals, the thick layer of blubber underneath the skin acting as an
insulator. It also serves as a reservoir of fat. Lungs are present
instead of gills as in fish, meaning that Whales have to surface
periodically to breathe, though they can stay submerged for long
periods. The blowhole is used for this purpose, numbering in two in
case of Baleen Whales and one for Toothed Whales. Dorsal fin is often
present. Sometimes small hind quarters are also observed, possibly
vestigial like the pelvic bone, propulsion being done mainly by the
tail fins or fluke.
Classified as predators, Whales consume
plankton as their primary food source, though larger fish are often
taken. Tonnes of krill are consumed daily by the Blue Whale, the
largest creature in history. Highly intelligent animals, Whales often
live in groups called Pods. These pods contain greater number of
individuals in case of Toothed Whales that often move and hunt
together. Adult males are called Bulls, and females Cows. Annually
Whales migrate from the polar regions during winter season, traveling
thousands of miles in seas. Speed of movement is fastest in case of
Killer Whale or Orca, reaching up to fifty kilometers per hour. During
their aquatic activities, Whales display several moves including
Breaching where they jump above the water surface, possibly to get rid
of parasites, play or socialize. At times they may Skyhop, that is
raise their head above water and look around. Then there is Lobtailing,
when Whales stick their muscular tail out of water, move it around and
strike it on the water surface, possibly to send a warning through this
loud sound.
Whales reproduce slowly, taking on average an year
to give birth to a single offspring with a gap of two to three years
between births. Calves are born tail first to prevent them from
drowning and begin to swim almost immediately. In case of Blue Whales,
they weigh two tons at birth and gain two hundred pounds daily during
the first year of their lives. Mother feeds them through squirting the
breast milk into their mouth, in order to prevent wastage. Bond is very
strong between the calf and mother, who protects and feeds it up to one
year of age. Lifespan is between forty to hundred years normally,
though specimens older than two hundred years have been recorded,
making Whales the longest living of all Mammals.
The author is a blogger about mammals and an expert on whale. |
