Abstract
Long-rough dab were sampled during a period of one year at two stations situated 35 km apart in Balsfjorden, North Norway. The dab had ingested a total of 40 different prey taxa; 19 taxa were found at both stations. The polychaetes Nephtys sp., N:a19anidae (mainly Maldane sarsi), Owenidae (mainly Galathowena oculata), the amphipod Arrhis phyllonyx, the mysids Erythrops sp. and Mysis mixta, and ophiuroids (mainly Ophiura sarsi) were principal prey. The diet varied with season and with station. The long-rough dab in Balsfjorden had a more diverse diet than in more complex fish communities. The diet overlap with cod was low, and the two dominant demersal fishes in the fjord showed a pronounced resource partitioning. The long-rough dab seems to be an opportunistic predator with high capacity to change its realized niche according to prey availability and with the actual competition situation.
