Ecologists express concern as record-breaking rainfall this year has disrupted the Broadnose Sevengill shark nursery grounds in San Francisco Bay. These large, prehistoric-looking sharks are related to ancient species dating back to the Jurassic Period, approximately 300 million years ago. They inhabit tropical and temperate shallow waters and are found in oceans worldwide, except for the North Atlantic and Mediterranean Sea. Growing up to 2.9 meters in length, they exhibit sexual dimorphism with females being larger. Their diet is diverse, including other sharks, rays, fish, and marine mammals. The Broadnose Sevengill shark is classified as “Vulnerable” by the IUCN, warranting conservation efforts.
Facts/Terms for UPSC Prelims
- Shark Nursery: A crucial habitat where juvenile sharks grow and develop before venturing into the open ocean.
- Jurassic Period: A geological era that occurred about 201 million to 145 million years ago, known for the existence of various ancient species.
- Sexual Dimorphism: Differences in size, shape, or other characteristics between males and females of the same species.
- IUCN (International Union for Conservation of Nature): An organization that assesses the conservation status of species and provides guidance for their protection. “Vulnerable” indicates a species at risk of becoming endangered without conservation efforts.