Killer Whales

Whales are giant creatures that live in the sea. They look like fish, but are
not. Whales belong to the group of animals called mammals. Whales belong to the
group of mammals called cetaceans, which comes from a Latin word meaning large
sea animal. There are two major groups of whales. The first group is mysticeti
(baleen whales), and the other isodontoceti (toothed whales). In the group
odontoceti, there is a family of whales called delphinidae (dolphins and small
toothed whales). In this report, I will focus on a species of whale that comes
from this family, and that species is the killer whale, or also known as orcinus
orca, or just orca. The largest and most striking of the dolphin family, the
killer whale is one of the most fearsome predators of the deep. Killer whales
are basically the same shape as fish, but they differ in many ways. One of the
most obvious differences is the tail fin. Fish have vertical tail fins, while
whales have horizontal tail fins. One of the most distinctive features of orcas
is the tall, wide dorsal fin located on its back. In females, the dorsal fin can
grow to about 2 feet high. It is falcate (hooked or curved). In males, the
dorsal fin is triangular in shape and can grow up to about 6 feet high. Another
distinctive feature of killer whales is that they possess a sleek, black and
white pigmentation pattern. A white patch is located above and behind the eye.

An extensive white ventral patch extends onto the flanks (sides). "There is a
gray saddle behind the dorsal fin, which is black at birth." (Hoyt, Pg. 32) At
birth, orcas are about 2.1 to 2.4 meters long and weigh about 180 kilograms.

When they are adults, males grow to about 9.5 meters long weighing 8 tons or
more. Females grow to 8.2 meters long and weigh 4-6 tons. "Orcas have robust
and graceful bodies with a conical or rounded head." (Hoyt, Pg. 97) It has no
distinct beak. They have straight mouthlines. Another physical attribute of
killer whales, besides having a tall dorsal fin, is that killer whales have
large, paddle-shaped flippers. These flippers are 2-3 times larger in males than
they are in females. Killer whales are very large physical specimens. Being
known as a fearsome hunter with killer instinct, it would be interesting to know
what a killer whale’s diet consists of. The orca resembles the great white
shark in its predatory skill and range of food. They eat seabirds, turtles,
fishes, including sharks, whales, dolphins, porpoises, seals, and sea lions.

These hunters feed in groups of two to twenty animals. They can even kill baleen
whales much larger then themselves. They have 10 to 13 teeth on each side of
each jaw, which helps in their feeding. Though killer whales sometimes attack
dolphins, seals, and other whales larger than themselves, but they have not been
known to attack people, although there have been documented cases of killer
whale attacks. Throughout the ages, whales have lost some of the characteristics
of mammals. Mammals have hair covering their bodies. Whales have only a few
stiff hairs on their heads. Mammals have four legs. A whale has no hind legs.

The only traces that they remain are two tiny hipbones. The front legs have
developed into flippers, which are used for steering or keeping its balance.

Although killer whales share the same characteristics as mammals, they also have
special features that allow them to live in the water. Whales have many special
characteristics suited for living in the water. Living in water enables them to
reach enormous sizes. "The buoyancy (lift) of water helps support a whale’s
body, which makes it possible for them to grow larger." (Ellis & Knoph,

Pg.18) Orcas have a highly streamlined shape. This enables them to swim with a
minimum of resistance. The powerful tail fins called flukes are horizontal.

Whales swim by moving the flukes up and down. Another characteristic that is
helpful to killer whales, or any type of whale, is that a whale\'s backbone,
ribcage, and shoulder blades resemble those of other mammals. Almost all mammals
have seven neck vertebrae. In killer whales, these vertebrae are compressed into
a short length or joined together into one bone. This keeps the head from moving
about. It also joins the head directly to the body. Orcas have smooth, rubbery
skin that easily slips through the water. Mammals have hair to keep them warm.

Whales have only a few hairs on the head. To keep warm, they have a layer