What is "polybius henslowii"

Nipper \Nip"per\, n.

1. One who, or that which, nips.

2. A fore tooth of a horse. The nippers are four in number.

3. A satirist. [Obs.]
   --Ascham.

4. A pickpocket; a young or petty thief. [Old Cant]

5. (Zo["o]l.)

   1. The cunner.

   2. A European crab ( Polybius Henslowii).

Polybius henslowii is a species of crab, the only species in the genus Polybius. It is a capable swimmer and feeds in open water in the north-east Atlantic Ocean and western Mediterranean Sea.