Sticklebacks - Gasterosteiformes

Characteristics:

Sticklebacks have no scales, some species have bony armour plates. The most characteristic feature, however, is the isolated spines in the dorsal fin.

Taxonomy:

There are only three sticklebacks in the Norwegian fauna. The only marine species are the fifteenspined stickleback and the threespine stickleback (Gasterosteus aculeatus).