Undersøkelser av Gonatus fabricii (Lichtenstein) i Norskehavet og det vestlige Barentshavet i juni-september 1979

Abstract

Investigations on Gonatus fabricii (gonatus) continued in 1979. Material was collected during postlarval and 0-group fish surveys. The distribution of gonatus was very similar to that found in 1978. During June-July, small gonatus were abundant in the northeastern Norwegian Sea, maximum 4000 specimens in half hours' hauls with a Harstad trawl, 18 x 18 m opening. Recordings with a Simrad EK-120 echo sounder and integrator showed highest intensity in the area of maximum catches. In June-July mantle lengths were mostly 5-50 mm, maximum at 15-19 mm with average length 28 mm, but a few larger individuals, up to 80-84 mm, were found. Preliminary countings of growth rings in the statoliths indicated an age of 30 days for gonatus with mantle length 15 mm, 45 days for lengths of 25-35 mm, 65-75 days for lengths of 40 mm and 80 days for 50 mm. The results are given with reservation. Stomach contents were dominated by amphipods, copepods and chaetognaths. Other organisms identified were euphausiids, pteropods, mussel larvae, fry of Sebastes and tentacles of gonatus.