Wobbly Blue MarbleThe planet, explained for curious children.

Animal · United States, Portugal, Spain

Deep-sea anglerfish

Melanocetus johnsonii — the name this animal has in the language scientists everywhere share.

The deep-sea anglerfish hunts in cold black water far below the sunlight, using a glowing lure that hangs from a thin rod on its head. Its huge mouth and stretchy stomach let it swallow animals bigger than itself.

Where does the deep-sea anglerfish live?

Home: Dark open water of the deep sea.

In the wild it lives in these countries: the United States, Portugal, Spain, South Africa, Japan, New Zealand.

Conservation status from the IUCN: not in danger.

The short profile

Fully grown: females up to about 18 cm long. It weighs about 0.1 kilograms. On the menu: meat.

The story behind it

Between about 200 and 1500 metres down there is no daylight left and meals are rare, so the anglerfish waits instead of chasing. The rod on its forehead is a made-over fin spine, and the little bulb at the tip is packed with bacteria that give off light. The fish can twitch the lure so that it looks like a small swimming animal. When something comes close, the jaws snap open in a fraction of a second and water rushes in, carrying the prey with it. Long, thin teeth bend inwards, so nothing can back out again. A stomach that stretches like a bag means one big meal can last a long time. Only the females carry a lure; the males are tiny, have no lure at all and spend their lives searching for a female by smell.

Find it on the globe

Deep-sea anglerfish is there as a tiny animated figure that breathes and looks around. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.

It sits at its real coordinates, not near them — the same numbers listed in the facts above. Switch off the layer for this kind of place and it disappears again; the buttons for that are down the right-hand edge.

Questions children ask

How can the lure glow?

Billions of bacteria live inside the little bulb and make light with a chemical reaction. The fish gives them a safe home and food, and in return it gets a lamp it can carry.

Why are the males so small?

A male never fishes with a lure, so he needs neither a big body nor big jaws. Instead he has large eyes and huge nostrils that help him follow a female's scent through the dark.

Could I ever see one alive?

Almost never. They live far too deep for divers, and most are known only from specimens in nets or from short films made by remote-controlled submarines.

Where these numbers come from

Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.

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