• Sharks have been around for millions of years, they appear in fossil records.

• Sharks belong to a group of creatures called the cartilaginous fishes. Their skeleton is made from cartilage rather than bone. They have flexible tissue in their teeth.

• The earliest fossil evidence dates back to 450 million years ago. The earliest shark teeth dates back to 450 million years ago

• During this lifetime, sharks can produce between 20,000 and 40,000 teeth.

• Sharks have survived all 5 major extinction events.

• Sharks have adapted to the environment with 6 highly refined senses such as 

  • Smell

  • Hearing

  • Touch

  • Taste

  • Sight

  • Electromagnetism

Smell

• Most acute smell

• They could smell a single drop of blood in billions of drops of water.

• Nostrils are on the underside of the snout. Leads to an olfactory bulb.

Hearing

• Ears are in two small opening behind and above the eyes

• Can sense vibration in the water and around them

• Sharks have an ‘ear stone’ that responds to gravity, it gives clues to the animal to head up/down or right side up/down.

Vision

• Retina is divided into two areas

  • One is adapted for day vision

  • Other is for low light/ night vision

- sharks can roll their eyes backward or into the socket if they feel threatened. 

Electroreception

• Can sense an electrical field 

• Can use this to navigate through the open ocean by following an electrical map

Taste

• Hunt seals, sea lions, fish, and squid. 

• They have taste buds in their mouths/ throats to identify food before consuming 

Touch

• Lateral line: line that extend along the sharks head to tail

• Perceive vibrations