The sharks have inhabited the planet since 400
million years ago, these unpredictable animals have always generated fear
because of the little and scattered information available.
Bull sharks are recognized by the following characteristics: in the middle part
of the body are wider than other sharks, they are grey on top and white on the bottom,
have 2 dorsal fins, the front one larger. The nose is wide and round, not
pointed like other sharks, they reach up
to 2.5 meters and weigh up to 250 kg, females are larger than males.
They are viviparous (embryos develop in the placenta),
in the Playa del Carmen area sharks aree born at the end of the spring and
early summer. Gestation time is 11 or 12 months, and sharks come to have from 1 to 13 babies.
The size at birth varies between 60 and 80 cm in length. Sharks become sexually
mature between 10 and 15 years. They manage to live an average of 32 years.
Sharks have incredible sensory systems that
makes them great predators:
• Vision: they have a poor sense of sight,
but they can feel movements of shadow and light. Even in the night.
• Hearing: Hearing is acute, they can perceive low frequency sounds and
determine the direction where it comes from.
• Olfaction: They can perceive the presence of small quantities of certain
substances such as blood of other fish and determine its origin.
• Touch: Sharks impact objects with the nose to determine whether they are
edible or not.
• Taste: Sharks have taste cells in the mouth and throat that allows them to
discern between the edible and inedible.
• Electroreceptors: (Lorenzini ampoules) They come along from the brain tthough all the
body in a lateral line, which serves to capture waves and vibrations over great
distances. Like a fish that do not swim well or are injured.
The more knowledge we have of these animals
the more we can be in harmony with them and stop destroing them.
Recently shark populations has decreased, sharks are caught only to cut off
their fins and then thrown into the sea in order to use this part of their body
as exotic food.
Beyond our fears, each time we become more aware that the human
being is not part of the shark´s diet. A bad reputation of killers has been created around sharks, however
we have witnesed in our recent experiences, a behavior in which the shark
interacts with us, being an interesting and surprisingly harmless species.
Bull Sharks have been classified among the
three most dangerous shark species (white, Tiger and Bull. However it is
important to understand that most of the attacks that have been attributed to
the bull shark, apparently, have occurred in shallow waters with poor
visibility. For example: the mouths of rivers, lagoons and estuaries. These
attacks have been partial and are considered more a confusion that a purpose of
power.
The statistics allow us to deduce that more people are killed by the impact of
a lightning strike than by interaction with sharks (Rio de Janeiro-a total of
75 Brazilians died victims of lightning in 2008). According to the
international shark attack files, there are recorded about 70 attacks per year
of which 15 to 20 are fatal. In what it
refers to divers; There have been a total of 243 attacks since 1580 of which
only 36 were fatal.
It is estimated that an average of 100
million sharks are killed each year: therefore human being becomes the main and
biggest threat to this species.
We are fortunate to have them here in Playa del Carmen year after year; to be
able to observe them, learn from them and keep a record of their behavior in
order to help in their preservation for future generations.
HELP US TO CARE FOR THEM!