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181

deep sea

OLogy Series
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card
181

deep sea

OLogy Series
place

Far beneath the ocean's surface is a mysterious world of cold temperatures, intense pressure, and almost total darkness. The deep sea remains largely unexplored and unknown to humans. Yet billions of creatures live in this vast, dark void. Many of these animals have bizarre adaptations that help them hunt for the limited food and survive in extreme conditions.

Glowing in the Dark
In order to survive in this sunless world, 90 percent of all deep-sea animals have the ability to generate their own light, called bioluminescence. Bioluminescent light is produced by chemical reactions in living things. Bioluminescence helps animals attract a mate, find food, and avoid predators. Many fish hide by matching the glow of the dim light around them. Other animals use bright flashes to distract predators. Some squirt out clouds of glowing particles to divert predators while they sneak away. Using light for a variety of purposes, the animals of the deep create a dazzling light show that resembles a starry night sky.

All deep-sea fishes are:

carnivores (eat only animals)

herbivores (eat only plants)

omnivores (eat both animals and plants)

Are you right?

Correct!

All deep-sea fishes are carnivores, but they have very different adaptations to help them catch their prey. Tunicates, for example, collect sea snow (falling animal bits) with sticky mucus nets.

Many deep-sea fishes can swallow creatures bigger than themselves.

Fact
or
Fiction
?

Fact

Many deep-sea fishes can swallow creatures bigger than themselves. Some can stretch their expandable mouths to 10 times the size of their bodies!

The deep sea covers over half of the Earth's surface.

Fact
or
Fiction
?

Fact

In fact, 60 percent of the Earth's surface is covered by water more than 3,000 feet deep.

Definition: the vast, deep region of the ocean
Depths: from 200 meters below the surface to the
ocean floor
Conditions: dim light or total darkness, intense pressure, cold temperatures
Where: in all the oceans of the Earth
Inhabitants: billions of creatures, including carnivorous fish

Image credits: Sean Murtha.