Prehistoric Extinct Sharks
SHARK CHAT FORUM
The Blue Shark is also known as
great blue shark,
requin bleu and Blue Whaler.
- BLUE SHARK
Scientific Name.... Prionace Glauca
Family Name...... Carcharhinidae
- General Information: The blue shark is large
and slender with a indigo blue upper body. With its long , narrow,
and pointed pectoral fins, long snout, and large eyes, it is
- Size: The maximum reported size is 13 feet,
but the average blue shark are seldom over 8 1/2 feet. The size
at birth are from 13 to 19.6 inches.
- Teeth: The Blue Shark has long serrated teeth
which it uses to catch slippery prey, like squid and fish, which
make up the bulk of its diet.
- Color: The blue shark which is one of the most
attractive sharks and easily recognized by its distinct color
of deep indigo blue on its upper body and the sides are a bright
blue with a markedly white belly.
- Feeding Habits: Blue sharks feed ravenously
on large schools of squid. While feeding on the squid some blue
sharks will charge into the groups with their mouths agape, engulfing
large numbers of them. They also feed on pelagic fishes such as
cod, haddock, mackerel, tuna, herring and swordfish. However, this
species will also eat larger prey items, like small sharks, seabirds, box fishes
and daggertooth. It will also scavenge on dead cetaceans. The
blue shark has elongate papillae on the gill rakers that apparently
prevent smaller, slippery prey from escaping out of the gill slits.
Fish caught on long lines during fishing are often attacked and
consumed by blue sharks, who in turn often become ensnared in
the fishing gear. They may feed more actively at night, with highest
activity in the early evening.
- Senses: They have well developed sight, and
smell, and can detect electric currents given off by their prey.
They also have the senses of taste touch and hearing.
- Social Behaviour: Blue Sharks are aggressive,
and are considered to pose a threat to humans. They have been
know to attack people occasionally. Blue Sharks often form large
all-female, or all-male groups of sharks of similar size. No one
knows why they do this.
- Habitat | Migration | Distribution:
shark is found worldwide in the open oceans throughout the tropics
and into cooler seas. In the tropics it often enters deeper, cooler
water, as it prefers temperatures between 7 and 16 degrees
It comes close to the edge of kelp beds, where divers may see
them. This shark is often observed at the ocean's surface, however,
it can be found at depths down to 700 feet.
- Life Span: Maximum age is estimated to be at
least 20 years.
- Reproduction: Although not yet observed, blue
shark courtship is thought to be very lively. Males apparently
bite the females during courtship and possibly during the mating
act. Fortunately the females skin is about three times as thick
as the males. Mating occurs during late spring to early winter. Blue
sharks are viviparous, bearing live young ,fully formed. They mate
and store sperm for nearly a year, after which fertilization occurs.
Litters of from 4 to 135 pups, depending on the size of the mother,
are born alive the following year.
- Swimming: The blue sharks long, tapered body
makes it a very graceful swimmer. It has an elongated caudal fin,
which provides swimming power as it moves it's tail from side-to-side.
The blue shark is among the fastest sharks, and even the fastest
fish! It can even leap out of the water estimated at speed of
about 22mph, but others say they can reach speeds of 60mph. Not
enough studies have been done to know which is closer to the truth.
- Blue Shark Attacks: Although attacks are unlikely,
excited sharks have occasionally taken a nip at an unwary diver.
- Population Report: Previously very abundant,
now reduced by heavy fishing.