THE FOOD AND THE FEEDING-HABITS OF THE LONG ROUGH DAB, HIPPOGLOSSOIDES-PLATESSOIDES (FABRICIUS 1780) IN THE NORTH-SEA

The type and quantity of food, the feeding intensity as well as the di el feeding pattern of the long rough dab Hippoglossoides platessoides are described. The interaction of the species with the biological envi ronment is also assessed. The North Sea long rough dab feeds throughou t the year with a definite maximum from April till August when over 85 % of the fish sampled were feeding. It feeds principally on crustacean s (natant decapods), polychaetes, and echinoderms (ophiuroids), but al so consumes O-group whiting (Merlangius merlangus), long rough dab, an d gobies (Gobiidae) in the east-central North Sea nursery grounds duri ng the summer months. The species does not compete strongly for food w ith the other three most abundant pleuronectids, viz. plaice (Pleurone ctes platessa), common dab (Limanda limanda) and lemon sole (Microstom us kitt), as shown by a comparison of major prey items in their stomac hs and the anatomical structure of their digestive tracts. The differe nces in the diet between the North Sea population(s) of long rough dab and the population(s) of the species from other North Atlantic areas are probably a manifestation of ecological differences amongst these e cosystems, especially in the availability and the distribution of prey organisms.