Cephalopod dermal structures

Cephalopods exhibit various dermal structures on their mantles and other parts. These may take the form of conspicuous warts, cushions, papillae or scales, though in many species they are microscopic tubercles. The most elaborate forms are found among the oceanic squid of the order Teuthida.

Most cephalopod dermal structures take the form of tubercles, and these are the only cartilaginous dermal structures (the various "dermal cushions" being composed of other forms of connective tissue). All three main types of cartilage found in vertebrates are represented among the different squid species: hyaline, elastic and fibrocartilage. Tubercles of hyaline cartilage are primarily associated with cranchiid or glass squid.

The vast majority of cephalopod dermal structures have a thin, overlying epidermal layer, though this is often damaged or missing in captured specimens.

Other cephalopods with prominent dermal structures include: Brachioteuthis spp.; Galiteuthis glacialis (which has round tubercles); Histioteuthis meleagroteuthis and Histioteuthis miranda (tuberculate ridges); Mastigoteuthis danae (large tubercles in advanced paralarvae);Onykia aequatorialis, Onykia ingens, Onykia lonnbergii, and Onykia robsoni (irregular warts);Slosarczykovia circumantarctica (fibrous integumental net); and all members of the subfamily Cranchiinae (strips of cartilaginous tubercles in various arrangements). Among octopuses, Ocythoe tuberculata is noted for the tubercles and ridges on its mantle.

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