Daria Skaramuca

The age, growth and feeding habits of the European conger eel, Conger conger (L.) in the Adriatic Sea

Abstract This study determined basic biological data for the European conger eel Conger conger (L.) population in the coastal waters of the eastern Adriatic Sea. Juveniles and immature females dominated the coastal population, whereas males were relatively uncommon. The population structure determined by the study suggested spatial separation of sexes and spawning grounds in deeper waters. Both edge-type and marginal increment analyses confirmed the formation of a single growth annulus per year on the ground otoliths. The observed maximum age of the coastal conger eels was 8 years, although most of the sampled fish were 5 years old. The estimated parameters of the von Bertalanffy growth model suggested that the growth of the conger eels was relatively slow. C. conger is an opportunistic predator. Its diet was composed primarily of fishes, followed by crustaceans and cephalopods. Due to the evident site fidelity of the species, the wide prey spectrum of the conger eels (33 taxa) reflected the local benthic community structure.

Food preferences of the Mediterranean moray eel, Muraena helena (Pisces: Muraenidae), in the southern Adriatic Sea

Abstract The food and feeding habits of the Mediterranean moray eel, Muraena helena, collected in the southern Adriatic Sea by bottom longline fishing, were examined. Of the total 146 specimens, 37 had almost or totally empty stomachs. Muraena helena is a carnivorous species whose diet primarily includes benthic fishes and crustaceans. The diet consisted of at least 27 different prey taxa belonging to 8 major groups. The dietary preferences among the sexes and seasons did not differ statistically, but diet depended on age and reflected differences in prey availability. Also, diet composition significantly differed according to depth, with the cephalopod Octopus vulgaris occurring in the diet of morays caught just below 30 m, while crustaceans were more common in the diet of specimens sampled in shallower waters. Results indicated that M. helena is an opportunistic species that feeds on motile prey. Furthermore, a continuing study with a well-designed sample collection is needed to accurately assess the trophic status and the predatory impact of M. helena within the Mediterranean coastal communities.

Record of a live sharksucker, Echeneis naucrates (Osteichthyes: Echeneidae) from the south-eastern Adriatic (Croatian coast)

On 23 July 2007 a specimen of very rare live sharksucker Echeneis naucrates was caught in Ombla River near Dubrovnik, south-eastern Adriatic. First data on biometric lengths and morphology of this species are presented for the eastern Adriatic.

Lipid profiles of Mediterranean moray, Muraena helena, European conger, Conger conger, and European eel, Anguilla anguilla (Actinopterygii: Anguilliformes)

The current topics in fish fatty acid (FA) research include qualitative comparisons, trophic transfer as nutritive sources of FA, evolutionary comparison of synthesis pathways, and potential application of most efficient fish desaturases and elongases. FA are scarcely investigated in Elopomorpha and Anguilliformes, except for common- and Japanese eels. In this study determines the differences in lipid composition of FA between species of the order Anguilliformes, representing three families, Mediterranean moray, Muraena helena Linnaeus, 1758 ; European conger, Conger conger (Linnaeus, 1758) ; and European eel Anguilla anguilla (Linnaeus, 1758) (thereafter moray, conger, and eel, respectively). These are the first results on FA for the moray.