First record of Diaphus rafinesquii (Cocco, 1838) (Myctophidae) in the Norwegian Sea

The myctophid Diaphus rafinesquii is endemic in the North Atlantic and the Mediterranean and was for the first time found in the Norwegian Sea. The specimen was captured off northern Norway at about 71° N, representing the northernmost record so far. Meristic and morphometric comparisons showed no evident differences to specimens found in other areas of its distribution. Although the actual abundance and distribution of this species in Norwegian waters remained unclear, we emphasized the general high potential of mesopelagic species for indicating environmental short- and long-time changes by monitoring the faunal change.