Sharks’ ability to sustain life as the apex of the aquatic ecosystem for more than 400 million years speaks volumes about their physical and behavioral adaptations. This predator, known for razor-sharp teeth and swift movements, combines such attributes with a range of behaviors to carry on necessary processes inherent to survival and supremacy at the top of the food chain in the ocean habitat.
Sharks combine physical adaptations such as sharp teeth, heightened senses and a forceful body and tail with behavioral techniques to catch prey. Sharks are nocturnal predators of the ocean, feeding at night between low and high tide, and typically in shallow water near reefs.
Sharks implement different hunting strategies, depending on the species. For example, great white and angel sharks stalk and ambush their prey from the bottom, while hammerheads and makos chase their prey.
Sharks stun their prey with a bump or bite and either pull the prey underwater, thrashing it to incapacitate it, or swim away and wait for the prey to die before eating it to alleviate a struggle. Sharks use their speed, agility, body weight and the force of their teeth to attack their prey without exerting a large amount of energy. This helps them retain calories needed for migrating long distances, hunting and mating.
Sharks migrate, using electroreception, to survive and to reproduce. Sharks migrate seasonally to mate in breeding grounds and birth pups in nurseries. Pups are born throughout the late spring and summer and stay in nurseries for safety from predators until migrating south during the winter.
Most sharks, with the exception of great whites and makos, are cold-blooded mammals, meaning they rely on the water temperature to sustain their core body temperature. This causes sharks to migrate to the south during the winter and north during the summer to keep their body comfortable within a desired temperature range. Sharks also migrate to follow migrating food sources such as schools of fish and seals.
Sharks mate through face-to-face copulation, meaning they engage in intercourse while facing each other, primarily because their sex organs on their undersides. Male sharks dominate female sharks by biting the female in the pectoral fin and pushing her nose downward. This behavioral adaptation allows a male shark to overcome the female and position himself so that the male claspers make contact with the female cloaca to fertilize the eggs. The behavior occurs for about a minute until the male shark disengages and swims away.
Sharks use different types of body language to interact and communicate with one another and prey, showing signs of dominance or submission. Sharks stiffen and arch their bodies and open their mouths to exhibit a threat to other sharks and display swimming techniques such as turning away to dominate their own space. Sharks also communicate by slapping the water with their tails or by breaching out of the water, which are theorized as forms of discouragement toward other sharks that are interfering with prey. Some species of sharks such as hammerhead and bull sharks roam and hunt the waters in schools versus other sharks that are more solitary.