Seasonal variations of lipid and moisture content in relation to sexual cycle of round sardinella Sardinella aurita Valenciennes 1847 in the eastern middle Adriatic Sea

A total of 2,033 round sardinella specimens were analysed to examine their moisture and lipid content, condition and gonadosomatic index. Total length (TL) ranged between 10.0 and 32.5 cm (mean +/- SD = 22.0 +/- 3.65 cm). Lipid content started to increase in August, reaching its peak in October. Higher values continued during winter months and then declined in spring. GSI, condition and SST values indicated an inverse annual cycle in comparison to lipid content - increasing in spring and peaking during summer months. Mesenteric fat and lipid content showed similar annual pattern. The abundance of round sardinella has increased in the Adriatic Sea and Mediterranean, whereas Sardina pilchardus and Engraulis encrasicolus, economically important and abundant pelagic fish species, have been suffering marked declines in their populations. This directly affects the interspecies relations in the pelagic communities, as well as in the fish meal processing industries which have recently started to include round sardinella.