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Sticker of Giant isopod
Bug card No. 0593 of 1,500

Giant isopod

Bathynomus giganteus
Eats: Leftovers and dead thingsWoodlicePonds, rivers and shores14 legsNot an insect, but a bug cousin

The giant isopod looks like a woodlouse, but it is as big as a cat. It lives deep down in the cold, dark sea. Its big eyes seem to glow when light shines on them.

Fun fact: woodlice are not insects. They are crustaceans, cousins of crabs and shrimps, that live on land.
Lives in
Deep in the western Atlantic Ocean, the Gulf of Mexico and the Caribbean Sea
Length
19 to 36 cm (7.5 to 14 in)
Top speed
about 0.45 km/h (0.28 mph)
On foot, estimate
Can it hurt you?
Harmless
Harmless. It lives so deep in the sea that people almost never meet one.
What does it eat?
It eats dead sea animals that sink down to the sea floor. That way it helps keep the deep sea clean.
For real!Photo of Giant isopod
Picture by x768. CC BY-SA 2.0, via Wikimedia Commons.

How big is it?

How long is it?

Giant isopod about 36 cm long (14 in)A banana about 18 cm (7.1 in)A house cat about 50 cm (20 in)A dog about 1 m (39 in)
as long as 11 toy building bricks in a rowas long as 2 bananas end to endit has about 14 legscould run across a dinner table in 8 seconds

How big is Giant isopod compared to YOU?

Just maths in your browser. Nothing is saved or sent anywhere.

How fast is it?

cool stuff

Fun facts

1

It lives between about 300 metres and 2 kilometres under the water, where it is cold and dark.

2

Each of its eyes has more than 4000 tiny parts.

3

Animals in the cold deep sea often grow much bigger than their cousins and live longer. Scientists call this deep sea gigantism.

4

Its babies hatch looking like tiny grown-ups, but they are missing their last pair of legs.

5

The first one was found in fishermen's nets in 1879.

you asked

Most asked questions about Giant isopod

?How big is a giant isopod?

Usually about 19 to 36 centimetres long. The biggest one ever checked was about 50 centimetres.

?Is a giant isopod related to a woodlouse?

Yes. Both are isopods, and they are distant cousins of shrimps and crabs too.

?What does a giant isopod eat?

It eats the remains of dead animals that sink to the bottom of the sea.

For bug experts

Scientific name
Bathynomus giganteus
Named by
Milne-Edwards, 1879
Group
Woodlice
Family
Cirolanidae
Classification
Malacostraca > Isopoda > Cirolanidae
Lives on
North America

Where the facts come from

  1. Bathynomus giganteus (Wikipedia, CC BY-SA 4.0): what it looks like, where it lives, what it eats, sizes and fun facts, retold in simple words.
  2. Picture by x768. CC BY-SA 2.0, Wikimedia Commons. The round sticker of this bug is cut from the same picture.

If we got something wrong, sorry, we are bug fans, not a science journal. Tell us at hello@bugwiki.app and we will fix it.

More from the same group: Woodlice

Also at home here: Ponds, rivers and shores