(Linnaeus, 1758)
Description
Adult. Difficult to distinguish from Alloteuthis subulatus. Arms and tentacles tend to be proportionately more slender, but the chief characteristic by which the two species are separated is the lateral mantle edge, which in A. medius extends obliquely posteriorly between the dorsal and ventral margins. Adults have a short tail (less than 10 mm). Fin length with tail included is less than a half of mantle length. Club is wide, diameter of the largest club suckers is 9-14 % of the width of head. Pairs of central club suckers are attached almost perpendicular to the club axis.
Larvae/juvenile [A.medius-y ]. Description not available. Generally no great changes in body forms occur in development from hatchling to adult. (Hanlon et al., in Sweeney et al., 1992).
Size
Adult mantle length up to 70 mm; hatchling length ca. 2 mm. [Synopsis of sizes of Alloteuthis species from hatchling to adult Loligo-sizes-y ].
Distribution in the North Sea
Southern North Sea, maybe also in the northern North Sea.
World distribution
Lusitanian-Mediterranean, from the southern North Sea to Cape Blanc (Mauretania) and in the Mediterranean Sea.
Remark
As some authors regard Alloteuthis as a subgenus within Loligo, this would imply the present species to be Loligo (Alloteuthis ) media (Linnaeus, 1758). More to read under Genus Alloteuthis.