The distribution and biology of mysids in Icelandic subarctic waters as demonstrated by analysis of cod stomach contents

Abstract

Abstract The mysids occurring in the stomachs of cod (Cadus morhua Linnaeus, 1758) caught during March, September, October, and November 1981 and 1982 on feeding grounds in the subarctic shelf area north and east of Iceland have been examined. A total of 2163 individuals belonging to eleven species occurred in the 6637 stomachs which were analysed and found to contain food. Mysis mixta Lilljeborg, 1852 and Erythrops abyssorum G.O. Sars, 1869 were most numerous in the stomachs, constituting 57.1 and 27.7 % respectively of the mysids. The other mysids were, in declining numbers of abundance, Meterythrops robusta S.I. Smith, 1879; Stilomysis grandis (Goës, 1863); Boreomysis nobilis G.O. Sars, 1885; Pseudomma truncatum S.I. Smith, 1879; Erythrops erythrophthalma (Goës, 1864); Mysis polaris Holmquist, 1959; Erythrops microps (G.O. Sars, 1864); Parerythrops spectabilis G.O. Sars, 1885, and Pseudomma frigidum Hansen, 1908. Of all these species only M. mixta and P. truncatum have previously been recorded from the shelf area around Iceland. M. polaris, E. microps, P. spectabilis, and P. frigidum were only found in the stomachs of cod caught at the edge of the north-western shelf while the other species appear to be widely distributed off the north and east coasts. The smallest species probably have a one.-year life span while the larger species may live for two years or even longer in the case of B. nobilis. Females of most species carried larvae during the autumn and early winter months. The main breeding period could only be determined in the case of M. mixta where it was found to be between November and March.