mesopelagic

American  

[mez-uh-puh-laj-ik, mes-, mee-zuh-, -suh-] / ˌmɛz ə pəˈlædʒ ɪk, ˌmɛs-, ˌmi zə-, -sə- /

adjective

Oceanography.

1. of, relating to, or living in the ocean at a depth of between 600 feet (180 meters) and 3,000 feet (900 meters).

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mesopelagic British  

/ ˌmɛsəʊpəˈlædʒɪk /

adjective

1. of, relating to, or inhabiting the intermediate depths of the ocean between approximately 100 and 1000 metres

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Etymology

Origin of mesopelagic

First recorded in 1945–50; meso- + pelagic

Example Sentences

"These mesopelagic fish are doing the hard work of connecting the deep ocean to the surface food web. If we don't understand them, we're basically trying to solve a puzzle with the middle pieces missing."

From Science Daily • Dec. 28, 2025

Also known as the mesopelagic, it makes up a fifth of the ocean’s total volume, and much of it remains largely unexplored.

From National Geographic • Feb. 13, 2024

The quantity of mesopelagic life is large enough to play a significant role in the cycling of global carbon, scientists say.

From New York Times • Jun. 29, 2015

The mesopelagic zone extends from 200 m to 1,000 m; the bathypelagic zone from 1,000 m to 4,000 m; and abyssalpelagic zone is deeper than 4,000 m.

From Textbooks • Jan. 1, 2015

In the middle depths of the ocean—the mesopelagic zone that is located 200 to 1000 meters below the surface—the vast majority of organisms can bioluminesce.

From Science Magazine • Sep. 7, 2012