Cirolana cranchii

Cirolana cranchii was described by the English zoologist William Elford Leach in 1818; he named the genus anagrammatically after an unknown woman called Caroline/Carolina, and the species after his friend and collector John Cranch.[3][4]

C. cranchii is the type species of the genus Cirolana, which in turn is the type genus for the family Cirolanidae.[2] The type locality is Cornwall, Great Britain.[1][2]

The species is found around the British Isles and the northwestern coasts of Portugal, Spain and France, with the greatest abundance around the western coasts of Ireland, Cornwall and Brittany.[5] The species has also been recorded from the North Sea, the Mediterranean, and the coasts of Australia.[6] Bruce and Ellis consider only the eastern North Atlantic and Mediterranean records reliable.[2] Also reported from South Africa near Cape Town.[7]

The adult male is between 9.0 and 19.1 mm long and about 3 times as long as it is wide. The head (cephalon) lacks a forward-pointing spine (rostral process). The body consists of 11 visible segments each covered in a smooth dorsal scale behind the head, with a triangular tail (pleotelson).[2] There are six joints to the abdomen. The legs are used for walking and have small claws.[4] Tail paddles (uropods) extend beyond the point of the tail. The female has a wider pleotelson and non-angled uropods, and lacks the dense bristles (setae) on these parts. Females are between 9.6 and 19.2 mm long. Young males resemble females.[2]

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