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Interesting
Dolphin Facts
The Bottlenose Dolphin is probably the most well known
and most loved species of dolphin. They are found in the Pacific
Ocean from southern California to the tropics and in the Atlantic
Ocean from Nova Scotia to Venezuela and the Gulf of Mexico. They
feed on a variety of fish and have been known to follow fishing boats for
miles, feeding on discarded fish. While following the boats they playfully
jump and ride the boats bow wake.
The Bottlenose Dolphin is one of the largest species
of dolphins. Adults average 8 to 10 feet in length and can weigh
up to 450 pounds. They can eat approximately 65 pounds of food a day. When
swimming, they rise to the surface every 15 to 20 seconds to breathe however,
they can remain underwater for several minutes while riding waves or diving.
The Atlantic Spotted Dolphin closely resembles the Bottlenose
Dolphin in appearance. The Atlantic Spotted Dolphin, however, is generally
more blue and the dorsal region is darker and covered with many light blue
blotches or spots. Calves are born a solid color and develop spots as they
mature. Atlantic Spotted Dolphins can grow to be 8 feet long and weigh
275 pounds. They are very friendly dolphins and very curious. Like the
Bottlenose Dolphin, they will swim for miles alongside a boat riding the
bow wake and trying to investigate the people on board. Spotted
Dolphins are very sociable and easily mix with other species of dolphins.
They also like to be around yellowfin tuna schools, which has proven
to be dangerous for them. When fishing nets are dragged in, the dolphins
are often caught in the nets with the tuna. They are unable to escape
the fine nets. Since dolphins are air breathing mammals, they quickly
drown if they are unable to free themselves from the nets.
Laws have been passed in many countries that mandate the
use of "Dolphin-Safe" nets and
fishing practices. The nets are now made with a looser
weave and are pulled in more slowly to give the dolphins a chance to escape
over the top. Many time the dolphins are can be manually released from
the nets. Some Spotted Dolphins have been caught so frequently they have
become experts at escaping or they know how to rise to the surface and
patiently wait to be released.
The body of the dolphin is considered to be streamlined
perfection. The smooth skin has a rubbery feel and is hairless, therefore
providing no resistance while swimming through the water. The fins
are curved and have pointed tips. Flukes are well spread and also
have pointed tips. The flukes are used for propulsion and stability. Man
has studied the design of the dolphins flukes to help improve the effectiveness
of submarines and boat propellers.
Most dolphins species have jaws that protrude into a
snout that resembles a beak. Bottlenose Dolphins have 18 to 26 small,
sharp cone shaped teeth in the upper and lower jaw. A large mass
of fat and tissue rich in oils make up the melon or the bulge on the
forehead. Researchers once believed that the size of the dolphins melon
meant that dolphins had a large brain therefore accounting for their
superior intelligence. Because of their social nature and ability to ocalize
with a wide variety of sounds, researchers now believe that dolphins have
an intelligence level comparable to primates. Humans hope to someday
be able to communicate directly with dolphins using their own language.
Dolphins are found in all the oceans and seas of the world. Some species
are local to a
specific region, but others, such as the Bottlenose Dolphin
and Common Dolphin are found all over the world. In some places dolphins
are found in large numbers. As many as 30,000 to 50,000 White sided
Dolphins live off the coast of Japan. Many species travel together in groups
of a thousand or more. Bottlenose Dolphins prefer to swim in small groups
of less than a hundred. Sometimes they travel in family groups and do not
allow "outsiders" to travel with them. it is rare to find dolphins swimming
in the wild alone.
Dolphins love to vocalize. They produce two types of
sounds. A mechanism just below the blowhole allows them to produce clicks
which are quick, pulsating sounds. These clicks are used for echolocation
or dolphin sonar, to detect obstangles, prey or enemies in the water.
Dolphins also produce squeals and whistles from the larynx. The squeals
can change rapidly in pitch. Dolphins also whistle to communicate their
emotions to other dolphins so that they will react accordingly. Typically,
the whistles indicated a state of alarm or sexual excitement. Every
dolphin has their own distinct whistle. This is their
signature whistle. This is how dolphins know who is doing
the talking.
Whales and dolphins are warm blooded animals not fish.
They breathe with lungs and the feed their young milk produced in their
bodies. Dolphins resemble Porpoises, another sea mammal, and are scientifically
classed in the same family. All dolphins have a thick layer of blubber
under the skin that helps them maintain their body temperature. This
blubber also helps them keep afloat. Dolphins have excellent hearing, sense
of touch and sight. They can see well both in and out of the water.
Dolphins, however, lack the sense of smell and taste. Dolphins
do not hesitate to aid other dolphins that are injured or in danger. If
a companion is injured, other dolphins will rise beneath it and lift
to the surface to prevent it from drowning. In many instances where
a dolphin has been harpooned or injured, other have been seen chewing
and tugging on the spear in an effort to free the dolphin. There
have also been many accounts of dolphins rescuing humans lost at sea,
protecting them from sharks and helping them safely to shore. Dolphins
do not chew their food even though they have teeth. They use the teeth
to hold the food in place while their jaws crush it and shape it into a
cylinder like form that is then easily swallowed. Dolphin have to
swallow fish head-first. They will juggle the fish around to get
them into the correct position before swallowing them. If they do
not swallow them head-first, the fish bones can lacerate the dolphin's
throat as they are swallowed. Dolphins have very sensitive skin.
It is made up entirely of live cells, unlike human skin that is protected
against injury on the surface by dead cells. Dolphins bruise easily. When
bruised, it appears as if the dolphins have a wound or illness. Researchers
handling or releasing dolphins must take extra care not to bruise the animal
by bumping up against anything. Dolphins love to rub against each
other and the hands of humans but are careful not to bruise themselves.
Dusky
Dolphin
Duskies are a southern
hemisphere dolphin usually found in temperate waters and often seen
in large groups of hundreds. They use their bodies to help herd fish, in
a variety of leaps and water slaps. These leaps are also highly enjoyable
to watch and have earned the Duskies the title "acrobats of the sea".
They can be seen inshore
in the warmer months at Kaikoura New Zealand.
Dusky dolphins are not large, their
maximum length is 2.1 metres with average size being between 1.6m and 1.8m.
They have a very short beak and distinctive colourings.
They can be seen associating with common
dolphins, bottlenose dolphins, pilot whales, and other dolphin species.
As winter approaches they tend to move offshore and break up into smaller
groups.
Glossary
of Dolphin Words
Rostrum
The dolphins nose or snout. Not used for smelling. The
rostrum is hard like a baseball bat. It is used for digging
and attacking enemies.
Blowhol
Breathing hole located on the top of the head. Also used for
making sounds.
Melon
The dolphin's forehead. Contains a fatty substance and is used
for echolocation.
Dorsal Fin
The fin located on the top of the dolphin's back. It is used
to help the dolphin maintain balance in the water.
Pectoral fins
The fins located on either side of the dolphin. They contain
five finger like bones, joined to skeletal structure with ball and
socket joints. They are used for steering and stopping.
Flukes
The fins located at the end of the dolphin's tale. They move
in an up and down motion to propel the dolphin through the water.
Blubber
A layer of fatty skin which helps the dolphin maintain
body heat in the water.
Genital, Anal, and
mammary slits
Openings on the belly of the dolphin which allow them
to defecate, urinate, mate and nurse. Males have separate genital and anal
slits. Females have one long genital/anal slit and a mammary slit
on each side of it.
Calf
A baby dolphin.
Pod
A group of dolphins that normally swim, hunt
and play together.
Echolocation
A dolphin's sonar, clicks that emit through the dolphin's
melon and return an echo that is retrieved through the lower jaw. Dolphins
can determine the size, shape, speed, density and materials of an object
through echolocation.
Signature Whistle
Every dolphin has it's own distinct whistle. A
signature whistle is the same as the dolphin's name.
Baleen
In some whales, the fibrous plates in parallel rows on each
side of the upper jaw.
Cetacean
Member of the Order Cetacea, which includes whales, dolphins,
and porpoises.
Flippers
In cetaceans, the forelimbs.
Keel
A sharp ridge located, in some cetaceans, just
in front of the flukes.
Ventral
Pertaining to the belly, underside,
or lower part of the body.
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