In News:

A 20-year study in South Africa reveals that the decline of Great White Sharks disrupted marine ecosystems, causing cascading food web imbalances.

Key Highlights:

• Scientific Name:Carcharodon carcharias
• IUCN Red List Status:Vulnerable
• Habitat and Distribution:
  • Commonly found in temperate coastal waters, including regions off the USA, South Africa, Australia, and Japan.
  • Highly migratory, often venturing into tropical waters but returning to temperate zones for feeding.
• Key Biological Features:
  • Endothermic Adaptation: Capable of maintaining body temperature higher than surrounding waters (regional endothermy).
  • Body Structure: Streamlined, torpedo-shaped body with serrated teeth for efficient hunting.
  • Feeding Behavior: Ambush predator – uses a "bite-and-wait" strategy to hunt seals, dolphins, and large fish.
• Reproduction:

• Viviparous: Gives birth to live young.
• Gestation Period: Around 12 months.
• Maturity:
  • Females: Mature at 15–16 feet, around 12–18 years of age.
  • Males: Mature at 11–13 feet, around 10 years of age.

• Ecological Importance:

• Apex Predator: Plays a crucial role in maintaining the balance of marine ecosystems by regulating populations of prey such as seals and mid-level predators.
• Indicator Species: Their presence signals the health and stability of marine ecosystems.

• Ecological Disruption in South Africa – Key Findings:

• A 20-year study in False Bay, South Africa, revealed a significant decline in Great White Shark numbers.
• This led to:
  • A surge in seal populations and sevengill sharks.
  • A corresponding collapse in populations of smaller sharks and fish, showcasing a trophic cascade and food web imbalance.