FaunaHub
Depth zone200–1,000 m

Twilight Zone

Mesopelagic zone

Below the sunlight zone, only faint blue light filters down and photosynthesis is no longer possible. Many animals rise toward the surface at night to feed.

Conditions in this zone

  • Depth: about 200–1,000 metres
  • Light: dim and blue, fading to darkness; no photosynthesis
  • Cold water and steadily increasing pressure
  • Home to the daily vertical migration of countless animals

Life of the twilight zone

Many squid and jellyfish range into the twilight zone, and some sharks descend here on deep dives. Bioluminescence — light made by living things — becomes common.

Animal profiles in this zone

Marine animals FaunaHub profiles that are documented in this zone. Many also occur in other layers.

Source & methodology

Zone science here is summarised from authoritative ocean-science sources. Animal placements reuse each species' verified source and show a confidence label; a depth zone is not treated as a complete range, since many animals move between layers.

Frequently Asked Questions

How deep is the twilight zone?
The twilight zone (mesopelagic zone) spans roughly 200–1,000 m.
Do these animals live only in the twilight zone?
Not necessarily. Many marine animals move between depth zones, some migrating vertically each day. We show the zone(s) each animal is documented to occur in, with a confidence label.

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