AGE, GROWTH AND FEEDING-HABITS OF THE BROWN COMBER SERRANUS-HEPATUS (LINNAEUS, 1758) ON THE CRETAN SHELF

Forty-five samples of the brown comber Serranus hepatus were collected during experimental surveys carried out on a monthly basis (August 19 90 to August 1992) along the Cretan continental shelf. A total of 1268 specimens 31-140 mm in total length were analysed. Growth was well de scribed by both standard and seasonalized forms of the von Bertalanffy growth model and the computed parameters were L infinity=152 mm, k=0. 36, t(o)= -0.57. Feeding intensity was high throughout the study perio d and varied significantly among the age classes of fish examined. Sto mach content analysis revealed that S. hepatus is carnivorous, feeding mainly on decapods. Diets did not vary seasonally; decapods were the most important prey throughout the year. However, the composition of t he prey consumed varied considerably with predator age coupled with di fferences in mean prey sizes utilized by each age class. The mean weig ht of stomach contents increased significantly for older specimens, wh ile the mean number of prey items decreased. Age-specific dietary sele ction was primarily a function of body size of the predator and appear s to reduce intra-specific competition among the members of the differ ent age classes. The results suggest that S. hepatus plays an importan t trophic role as a macrophagic carnivorous species on the Cretan cont inental shelf. (C) 1998 Academic Press Limited.