Shark Adaptions
For over 400million years sharks have been adapting themselves perfectly for life in the ocean. Their varied habitats, diets and physiology has meant that for many of them, these adaptions have been slightly different.
The key adaptions are those that enable the shark to swim, breath, feed and reproduce.
Large squalene filled livers negates the need for a shark to have a swim bladder. The liver, up to 25% of the overall body weight, counteracts the weight of the dermal denticles, teeth and cartilage; and when combined with the lift provided by the pectoral fins allows the shark to manage its buoyancy.
Gills allow sharks to maintain their watery existence by providing a means for extracting oxygen from the water as it passes over them. The oxygen is absorbed by the blood in the gills and transported from there to the rest of the body.
The number of gills ranges as well as the placement of them varies amongst species. Benthic sharks, like the Wobbegong may have a spiracle behind their eyes, or 5 gills on their flattened ventral surface. The majority of sharks however have the openings on the side of the head at about midline.
Sharks can continue to pass water over their gills if stationary by opening and closing their mouths, ending the theory that they would die if they don’t swim continuously.
Many sharks are however required to move to ensure that blood can continue to circulate through the contraction of muscles.
Sharks are ectotherms, deriving their heat from that of the surrounding water. This means that their internal temperature may vary as a result of changes to their environment. They have a very low metabolic rate and are slow efficient swimmers, resulting in a low energy expenditure and subsequently require very little food.
There are exceptions to this in the Mako and the Great White. These sharks have a body temperature up to 8OC warmer than their surroundings and are faster swimmers. This is because they have a modified
The key adaptions are those that enable the shark to swim, breath, feed and reproduce.
Large squalene filled livers negates the need for a shark to have a swim bladder. The liver, up to 25% of the overall body weight, counteracts the weight of the dermal denticles, teeth and cartilage; and when combined with the lift provided by the pectoral fins allows the shark to manage its buoyancy.
Gills allow sharks to maintain their watery existence by providing a means for extracting oxygen from the water as it passes over them. The oxygen is absorbed by the blood in the gills and transported from there to the rest of the body.
The number of gills ranges as well as the placement of them varies amongst species. Benthic sharks, like the Wobbegong may have a spiracle behind their eyes, or 5 gills on their flattened ventral surface. The majority of sharks however have the openings on the side of the head at about midline.
Sharks can continue to pass water over their gills if stationary by opening and closing their mouths, ending the theory that they would die if they don’t swim continuously.
Many sharks are however required to move to ensure that blood can continue to circulate through the contraction of muscles.
Sharks are ectotherms, deriving their heat from that of the surrounding water. This means that their internal temperature may vary as a result of changes to their environment. They have a very low metabolic rate and are slow efficient swimmers, resulting in a low energy expenditure and subsequently require very little food.
There are exceptions to this in the Mako and the Great White. These sharks have a body temperature up to 8OC warmer than their surroundings and are faster swimmers. This is because they have a modified