The Life History of Thysanoessa raschii

Abstract

Thysanoessa raschii is a regular inhabitant of the Firth of Clyde. Adults are found throughout this area, generally in waters not less than 40 fms. deep. Those of large size, 23–25 mm., are apparently consistently found from year to year in Loch Striven in large numbers from October to January within 10 fms. from the bottom in waters of 40 fms. depth. Throughout the rest of the year they occur in small numbers in the tow-nets, and are seldom found at all during the summer months. On one occasion, however, February, 1926, several hundreds were fished in addition to large numbers of Meganyctiphanes norvegica at 40–60 fms. in the Cumbrae Deep.