Nucleic acids as indicators of nutritional condition in the Norway lobsterNephrops norvegicus

Changes in nucleic acid concentration of the gill, hepatopancreas and abdom inal muscle tissue of the Norway lobster Nephrops norvegicus (L.) were exam ined after 6 and 12 wk of,starvation. Significant decreases in RNA concentr ation, RNA:protein ratio and RNA:DNA ratio were recorded in abdominal muscl e tissue following starvation, but not in gill or hepatopancreas tissue. Sa mples of abdominal muscle tissue were taken from lobsters from 2 sites in t he Clyde Sea area, Scotland. These were south of Ailsa Craig, where N, norv egicus are thought to be nutritionally limited as a result of the high popu lation densities that occur in this area, and south of Little Cumbrae islan d, where population density is lower. Evidence of nutritional limitation wa s provided by nucleic acid analysis which showed that the RNA concentration , RNA:protein ratio and RNA:DNA ratio of lobsters from south of Ailsa Craig were significantly lower than in lobsters of equivalent size from south of Little Cumbrae. Further studies demonstrated that animals from each site w ere capable of obtaining nucleic acid levels similar to those at the other site after a few weeks when exposed to different feeding regimes.