Strategies of Buoyancy in Sharks

Question 1

What is the specific gravity of sharks?

Answer 1

• 1.026 (close to SW)
• close to neutral buoyancy

Question 1

What low density compounds do sharks retain?

Answer 1

• large livers
  (lipids SG = 0.9-0.92)
  (squalene SG = 0.86)

Question 2

What do sharks lack?

Answer 2

• gas bladder

Question 3

How do sharks generate lift? (3)

Answer 3

• heterocercal caudal fin
• pectoral fins position angle of attack
• streamlining increases hydrodynamic efficiency

Question 4

What ancestral condition do sharks have?

Answer 4

• cartilaginous skeleton (SG = 1.1)