1. of, relating to, or inhabiting the ocean zone between approximately 200 and 1,000 meters (650 and 3,300 feet) in depth, characterized by dim light and moderate pressure
Usage: technical; oceanography

Examples

• Mesopelagic fish have adapted to survive in the dim light of the ocean's middle depths.
• The mesopelagic zone is home to many bioluminescent creatures.
• Scientists study mesopelagic organisms to understand deep-sea ecosystems.
• Mesopelagic waters experience significant pressure changes compared to surface waters.
• Many commercial fish species migrate through mesopelagic depths at night.