Local variations in size and activity among Calanus finmarchicus and Metridia longa (Copepoda, Calanoida) overwintering on the west coast of Norway

Vertical net hauls were taken at thirteen stations between latitude6008'N – 6120'N and longitude 0304'E – 0700'Ein late November 1980. Size and activity characteristics ofCalanus finmarchicus and Metridia longa were studied. Significantdifferences were noted between C. finmarchicus from differentstations. Average body length, dry weight, protein and lipidcontents, gonad development, and ainylase and trypsin activitiesvaried but average gut fullness and trypsin/amylase ratio appearedconstant. M. longa from different stations showed significantdifferences in average body length, dry weight, protein content,amylase and trypsin activities and gut fullness, but there wereno apparent variations in lipid content and trypsin/ainylaseratio. Those animals inhabiting the most seaward station tendedto show the most specific local charactenstics. M. longa hadconsistently lower lipid proportion with higher gut fullnessand digestive-enzyme activities than C. finmarchicus. The resultstherefore indicate that C. finmarchicus had assumed a winterstate of low activity with dependence on stored energy, whileM. longo relied more upon utilization of available food.