Our animals

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Northern lakes and seas

The ocean

Tropical rivers and lakes

Select aquaria

The Pond

The lake

The wide creek

Select species

Select a species to read more


Water flea

Water flea

European perch

European perch

Alpine bullhead

Alpine bullhead

Three-spined stickleback

Three-spined stickleback

Swan mussel

Swan mussel

Goldfish

Goldfish

Oriental carp

Oriental carp

Belica

Belica

European crayfish

European crayfish

Bitterling

Bitterling

Gudgeon

Gudgeon

Bitterling

Bitterling

Facts

LatinRhodeus amarus
Size9.5 cm
FoodAquatic plants and insects
HabitatPonds and slowly running parts of streams
IUCN

Least concern

LocationEurope
Map

The mussel as babysitter

The female bitterling uses a long ovipositor to lay eggs inside mussels. This keeps her eggs protected from predators and makes sure they get plenty of fresh water, which is pumped in by the mussel. The newly hatched young remain inside the mussel until they can survive on their own.

A swimming pregnancy test

The bitterling can reveal whether a woman is pregnant. When urine from a pregnant woman is injected into a female bitterling, it causes the ovipositor to protrude, because the fish thinks it is spawning. For this reason, the bitterling was once used for pregnancy tests.


Sturgeon

Danish stream

Danish lake

Herrings in the Sound

Boulder reef in the Sound

Stone reefs and jellyfish

Sandy bottom

Eelgrass in the Sound

Faroese bird cliff

Seaotter

Pacific octopus

Japanese spider crab

American lobster