WHALE:
Whales are large, intelligent, aquatic mammals. They
breathe air through blowhole(s) into lungs (unlike fish who breathe using
gills). Whales have sleek, streamlined bodies that move easily through the
water. They are the only mammals, other than manatees (seacows), that
live their entire lives in the water, and the only mammals that have adapted to
life in the open oceans.
Like
all mammals:
- Whales breathe air into lungs,
- Whales have hair (although they
have a lot less than land mammals, and have almost none as adults),
- Whales are warm-blooded (they
maintain a high body temperature),
- Whales have mammary glands with
which they nourish their young,
- Whales have a four-chambered
heart.
The biggest whale is the blue whale, which grows to be about 94 feet (29 m) long - the height
of a 9-story building. These enormous animals eat about 4 tons of tiny krill
each day, obtained by filter feeding through baleen. Adult blue whales have no
predators except man. The
smallest whale is the dwarf sperm whale which as an adult is only 8.5 feet (2.6
m) long.
Cetaceans include the whales, dolphins and porpoises. There
are over 75 species of Cetaceans. Whales belong to the order Cetacea (from the Greek word "ketos"
which means whale).
