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).

---

mesopelagic British  

/ ˌmɛsəʊpəˈlædʒɪk /

adjective

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

---

Etymology

Origin of mesopelagic

First recorded in 1945–50; meso- + pelagic

Example Sentences

See Examples For:

mesopelagic

"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

Ms. Justino has excavated fibers and beads from the digestive tracts of lanternfish, hatchetfish and other fish that migrate up and down in the mesopelagic, 650 to 3,300 feet down.

From New York Times ● Apr. 3, 2022

This dive will take place at night, when fish living in the deep ocean do their daily vertical migration to the mid-ocean, or mesopelagic zone, about 300 meters deep.

From Scientific American ● Mar. 3, 2014

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