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The blacktip shark
Carcharhinus limbatus.
© J. Staford-Deitsch / Shark Foundation
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Blacktip sharks are widely distributed in Florida and are the main
species of shark involved in accidents. Worldwide their numbers have
been extremely decimated due to increased overfishing and today they are
an endangered species.
Blacktip sharks have a relatively pointed snout and their
first dorsal fin is high. They have small eyes and conspicuously long
gill slits. Contrary to other representatives of their family they have
no interdorsal ridge between the first and second dorsal fin. Depending
on where they are, their basic color changes from light to dark, whereby
the bands on the flanks always remains clearly visible.
Despite their name the tip of the anal fin is not black but either gray
or white.
Blacktip sharks belong to the more short-lived
species, having an estimated life span of 12 years. Their average length
is approximately 150 cm, their average weight approximately 18 kg,
whereby animals measuring 250 cm have also been sighted.
Their
main prey are fish, e.g. sardines, herring, mackerels or even flatfish.
On rare occasions the remains of crustaceans, mollusks or even small
sharks have been found in stomach analyses (soupfin sharks, sharp-nose
sharks, young soupfin sharks, etc.).
As with all species in
the Carcharhinidae family - except the tiger shark (Galeocerdo cuvier) -
blacktip sharks are viviparous and have a yolk-sac placenta. They
usually bear between four and seven young, with large females being able
to bear up to ten pups. The gestation period its between 10 and 11
months and the size of the pups at birth is approximately 40 to 70 cm.
Because of their short life span, blacktip sharks mature at the
relatively early age of four. Research has shown that the females only
bear young every two years. The pups are born in the coastline regions
and grow rapidly.
Blacktip sharks are distributed worldwide
in tropical and subtropical oceans. They are usually found on the
continental shelves, but have also been seen around Hawaii, the
Galapagos and other island groups in the Pacific.
Blacktip
sharks live mostly on the surface and are seldom found in depths over 30
meters. They are also frequently seen in front of estuaries and bays
where larger saline differences prevail. They belong to those species
which often spring out of the water while hunting or while trying to
free themselves of remoras. Single populations of this species undergo
longer migrations so that they are found in certain locations frequently
during specific times of the year, but the migrating populations are
separated according to age and stages of gestation.
Although blacktip sharks, at least in Florida, is the species of shark
most commonly involved in accidents, the bites of these relatively small
sharks do not pose any real danger to humans.
Blacktip sharks are fished commercially worldwide and must be considered
an endangered species.
May be published only by indicating the source: Shark Info / Dr. Erich K. Ritter
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