Asian shore crab

Crabs found while playing on the shore.

Scientific name	Hemigrapsus sanguineus
English name	Asian shore crab
Japanese name	磯蟹
Class	Malacostraca
Order	Decapoda
Family	Varunidae
Genus	Hemigrapsus
Species	sanguineus
Full length	Approximately 25mm
Distribution	Widely distributed in the Western Pacific

Asian shore crab Characteristics and Morphology

The body color ranges from reddish-purple on the back to the walking legs, with green and yellow mottled patterns. Most are less than 3cm, but some individuals grow to about 4cm.
The left and right claws are the same size. They have a flattened carapace. The ventral side is whitish. The walking legs have light brown parts.

Male

Males have a narrow abdominal flap.

Female

Females have a wide, oval-shaped abdominal flap.

Asian shore crab Ecology

Habitat

Commonly found along the coast. They inhabit rocky areas and gaps in tetrapods.

Food

They are omnivorous and eat anything, including seaweed, small fish, and shellfish.

Life Cycle

They breed from late April to summer.

Asian shore crab Photos

Asian shore crab Photos are introduced.
Tap the photo to open the detail page.

There are yellow mottled patterns on the carapace and legs.

It hurts even if it is small when pinched.

Asian shore crab Behavior

They hide from natural enemies such as birds and black sea bream. They also compete with each other for food and territory.

Asian shore crab Information

Naming

The scientific name 'sanguineus' means 'blood red' and is derived from the color of the carapace and walking legs. In Japanese, it is also called 'Hanasaki crab' because it turns a bright red color when boiled.

How to eat Hemigrapsus sanguineus

Although not an edible crab, it can be eaten in miso soup. You can catch them near fishing spots, so you might as well eat them. Since they can be easily caught on the shore, you can take them home and keep them as pets. Hemigrapsus sanguineus will die in fresh water, so they must be raised in seawater. Keep the water clean and feed them small fish and shellfish. It is necessary to prepare artificial seawater at a pet store, etc.

Asian shore crab Found Locations

Kujūkuri Beach, Chiba Prefecture

I caught it on the tetrapods at Katakai Beach on Kujūkuri Beach in Chiba Prefecture. It was a Hemigrapsus sanguineus with a carapace size of less than 3cm, and it was easy to catch, but it hurt when my finger was pinched by its claws. There were also larger ones than this individual, but I was too scared to catch them with my bare hands. There were many things that Hemigrapsus sanguineus would like on the tetrapods, such as seaweed and shellfish.

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