THE ANIMAL FILES

Chinese mitten crab

Eriocheir sinensis

A freshwater feeding life leads downstream to breeding.

Chinese mitten crabs are recognised by dense dark bristles on the claws. Much of life is spent in fresh water, but breeding leads downstream towards brackish and marine conditions. Different stages therefore encounter different waters.[1]

Follow the evidence ↓
Chinese mitten crab
Image: Christian Fischer · Commons · CC BY-SA 3.0
Mittens made of setae
Dark bristles cover the claws.[1]
A downstream transition
Breeding migration leads towards the sea.[1]
From larva to small crab
Early stages drift before entering freshwater growth areas.[1]

Mittens made of setae

The so-called fur is a dense patch of setae on the claws. These are external bristles, not mammalian fur. The feature gives the common name a visible basis without suggesting a relationship to furry mammals.[1]

A downstream transition

Adults leave freshwater feeding grounds and travel downstream for reproduction. Eggs are carried attached beneath the female's abdomen. This connects river growth areas with the more saline environments used during reproduction and early development.[1]

From larva to small crab

Larval stages drift in coastal or estuarine water, then progress towards juvenile crabs and freshwater habitat. The sequence should not be collapsed into a single water preference for all ages. Worms, molluscs, other small animals and dead organic material contribute to omnivorous feeding.[1]

A COMMON MIX-UP

Is the claw covering mammal-like fur?

No. It consists of crustacean setae, and the NCBI lineage is arthropod.[1][2]

TRY A LITTLE REASONING

Why is a barrier between river and estuary relevant to this crab's lifecycle?

Reveal the explanation

Different stages use connected freshwater and saline environments, so the migration route links growth and reproduction.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Chinese mitten crab (cited revision)
  2. NCBI Taxonomy — Eriocheir sinensis

Last fact check:

One discovery leads to another

European green crabA green crab can be red—and still be the same species.Carcinus maenas ↗Atlantic blue crabAn estuary resident with an ocean-going beginning.Callinectes sapidus ↗Japanese spider crabLong legs are not the same measurement as a wide body.Macrocheira kaempferi ↗