are often regarded by many people as saltwater dwelling
animals. Contrary to popular belief though, there are
some sharks that are considered freshwater sharks. There
are two types of sharks that are considered freshwater
types, the bull shark and the river shark.
two types, the bull shark is by far more known. They are
considered an aggressive type and may attack humans at
the slightest provocation. The risk to humans is even
more pronounced since bull sharks prefer warm waters that
are shallow or close to the coast or shore. It is
therefore inadvisable to risk taking a dip in a water
region where bull sharks may have been sighted. Most
people though wouldn’t even know that there are such
creatures as freshwater bull sharks.
their label as freshwater sharks, bull sharks are not
considered true freshwater creatures. This is mainly
because studies have shown that these sharks travel from
the sea to freshwater sources. Some of these sharks also
travel back to saltier sections of water when they breed
or give birth to their young. Once the young sharks are
born, they can travel to freshwater sources themselves.
Since they do not stay exclusively in fresh water, bull
sharks are considered saltwater animals that are able to
tolerate freshwater conditions.
sharks survive in fresh water by regulating the amounts
of urea, sodium and freshwater in their bodies. They
regularly and frequently excrete sodium and urea to make
their bodies more adaptable to fresh water conditions.
They also urinate a lot to get rid of the fresh water
that enters their systems through osmosis. Some would
suggest that the stress placed on the kidneys by this
adaptive behavior push bull sharks to travel at regular
intervals to salt water sources. There have been some
bull sharks however that have been found residing in
freshwater sources for many years without traveling back
to saltwater regions. In fact, some bull sharks live the
rest of their lives in fresh water after being
freshwater sharks, bull sharks have come to adapt to
their situation in other ways. Since freshwater areas can
change temperature and offer different or limited food
sources, bull sharks grow no bigger than 7 or 8 feet.
bull sharks, river sharks are considered true freshwater
sharks. This means that these sharks have been found to
have the ability to live and reproduce independent of
saltwater regions. River sharks have not been known to
cross over to the sea from their freshwater homes. River
sharks are currently believed to live only in some parts
of Asia and Australia. Among the identified types are the
Irrawaddy, Speartooth and Ganges sharks. Unfortunately,
not much is known both about these identified types and
other unidentified ones. River sharks are considered very
rare. One can only therefore make assumptions about these
true freshwater sharks.
Water Sharks are truly amazing creatures. After having
survived for millions of years, they continue to adapt to
their environments to promote continued survival. The
bull and river sharks are
proof of how resilient fresh water sharks can