Shark Physical Characteristics and Senses

Study Notes

Sharks have a streamlined, torpedo-shaped body that reduces drag and allows for efficient swimming.
They have a cartilaginous skeleton, which is lighter and more flexible than a bony skeleton.
Their skin is covered in denticles, tooth-like scales that reduce friction and improve swimming efficiency.
Sharks have a horizontal tail, which they use to propel themselves through the water.

Sharks have exceptional senses, including:
- Electroreception: the ability to detect electrical signals from other animals, using specialized electroreceptors called the ampullae of Lorenzini.
- Smell: sharks have a highly developed sense of smell, which they use to detect prey and navigate.
- Vision: sharks have a wide field of vision, but their visual acuity is limited.

Sharks are apex predators, which means they have no natural predators in the wild.
They feed on a variety of prey, including fish, squid, crustaceans, and other marine animals.
Some species of sharks are specialized feeders, such as:
- Filter feeders: which use their gill rakers to filter small fish and plankton from the water.
- Ambush predators: which use stealth and camouflage to catch prey by surprise.

Sharks are generally solitary animals, but some species have been observed exhibiting social behavior, such as:
- Schooling: some species of sharks, such as the spiny dogfish, form large schools for protection and feeding.
- Mating: some species of sharks form aggregations for mating, which can be triggered by environmental cues.
Some species of sharks are known to migrate long distances in search of food, mates, or suitable habitats.

Many species of sharks are threatened or endangered due to:
- Overfishing: sharks are often caught accidentally in commercial fisheries, and are also targeted for their fins, which are highly valued in some cultures.
- Habitat destruction: sharks are often found in coastal ecosystems, which are vulnerable to human activities such as coastal development and pollution.
Conservation efforts, such as catch limits and habitat protection, are necessary to protect shark populations and maintain the health of marine ecosystems.

Streamlined, torpedo-shaped body reduces drag and allows for efficient swimming.
Cartilaginous skeleton is lighter and more flexible than a bony skeleton.
Skin is covered in denticles, tooth-like scales that reduce friction and improve swimming efficiency.
Horizontal tail propels sharks through the water.

Exceptional senses include electroreception, smell, and vision.
Electroreception detects electrical signals from other animals using ampullae of Lorenzini.
Highly developed sense of smell detects prey and navigates.
Wide field of vision, but limited visual acuity.

Apex predators with no natural predators in the wild.
Feed on fish, squid, crustaceans, and other marine animals.
Specialized feeders include filter feeders and ambush predators.
Filter feeders use gill rakers to filter small fish and plankton from the water.
Ambush predators use stealth and camouflage to catch prey by surprise.

Many species are threatened or endangered due to overfishing and habitat destruction.
Overfishing includes accidental catches and targeted fin catches.
Habitat destruction affects coastal ecosystems and sharks.
Conservation efforts, such as catch limits and habitat protection, are necessary to protect shark populations.