Polybius pusillus

Polybius pusillus, common name dwarf swimming crab,^[2] is a species of crab in the Portunidae family.^[3][1]

Polybius pusillus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Malacostraca
Order:	Decapoda
Suborder:	Pleocyemata
Infraorder:	Brachyura
Family:	Polybiidae
Genus:	Polybius
Species:	P. pusillus
Binomial name
Polybius pusillus (Leach, 1815)
Synonyms[1]
Liocarcinus pusillus (Leach, 1816) Macropipus parvulus (Parisi, 1916) Macropipus pusillus (Leach, 1816) Portunus parvulus (Parisi, 1916) Portunus pusillus (Leach, 1816)

Description

Polybius pusillus is a small, colourful species with a broad, suboval carapace having a maximum width of 25 mm (1.0 in). However, most specimens are usually less than 20 mm (0.8 in).^[3][4] This species occurs in a wide range of colours.^[3] The front has three sharpened tusks, directed forward.^[2]

Distribution

Polybius pusillus occurs from North-West Africa, to Lofoten, Norway^[3][4] including the North Sea.^[2] It is found around the shores of: England, in such places as Northumberland, Yorkshire, The Wash, Thames, the eastern English Channel, Isle of Wight, Portland, Plymouth, the Scilly Isles, the Bristol Channel, Liverpool Bay; Scotland - Shetland, Orkney, Firth of Forth, Argyll and Clyde, The Minch; Ireland, occurring in and around Dublin, Belfast, County Mayo, Galway Bay, Fastnet Rock, County Cork; and elsewhere in the British Isles including the Channel Islands, Anglesey and the Isle of Man.^[5]

Habitat

Specimens range intertidally up to 100 metres,^[4] dwelling on sandy to stony bottoms,^[3][5] but prefer gravel or stony substrates.