DK - WOW! The Visual Encyclopedia of Everything

The sunlit surface waters of many oceans teem with life,

most of it microscopic, that drifts with the currents. The whole

drifting community is called the plankton. It is made up of plant-like

phytoplankton, which use the energy of sunlight to make food from

carbon dioxide and water, and zooplankton – animals that feed on

both the phytoplankton and each other. This image shows the

plankton in a splash of seawater, magnified more than 25 times.

Plankton

This cyanobacterium is a

coiled chain of cells that

make food from water

and dissolved gas

The glassy shell of this

diatom reveals the green

structures that use solar

energy to make food

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CRAB LARVA

Among the members of the zooplankton

are the eggs and young of animals that

have very different shapes and lives when

adult. They include the eggs of reef

corals and infant fish, molluscs, and

crustaceans like this crab larva. Drifting

in the plankton provides them with food

and helps them disperse through the

oceans to find new places to live.

The size of a rice grain,

this crab larva is light

enough to drift near the

surface in the plankton

DIATOMS

The phytoplankton consist of

microscopic organisms such as diatoms

and cyanobacteria. Diatoms have shells

of glassy silica that fit together like tiny

boxes with lids, and they exist in a dazzling

variety of forms. They thrive in cool seas,

where they turn the water grey-green

and often multiply into vast cloudy

“blooms” that are visible from space.

CYANOBACTERIA

Once known as “blue-green algae”,

these simple organisms were among

the first forms of life to appear on

Earth, more than 3.5 billion years ago.

They still flourish in the oceans where,

like diatoms, they turn carbon

dioxide and water into

sugary carbohydrates.

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