Objective:To present the first information on the feeding habits of the Mediterranean needlefish Tylosurus acus imperialis(T.a.imperialis)of Tunisia and to examine the diet variation in relation to the fish size,matur...Objective:To present the first information on the feeding habits of the Mediterranean needlefish Tylosurus acus imperialis(T.a.imperialis)of Tunisia and to examine the diet variation in relation to the fish size,maturity and sex.Methods:Gut contents of 92 specimens of T.a.imperialis,collected mainly from May 2004 to July 2006 off the Gulf of Gabès,Southeastern Tunisian coast,were analyzed.Results:The results showed that 55.4%of them had empty guts and 44.6%contained food in their guts.The emptiness index did not vary significantly according to size classes or sexes of T.a.imperialis.Basic food consisted of teleosts(Mugilidae,Gobidae and Belonidae)(59.63%)followed by crustaceans(40.24%),mostly decapods Sycionia carinata(5.42%).A decrease in the feeding rate at the peak of the spawning season was observed for both sexes.A diet variation among juvenile and adult specimens of T.a.imperialis was found.Conclusions:This study enhances our knowledge on the biology of the Mediterranean needlefish T.a.imperialis.This fish is an active predator and an opportunistic feeder but the feeding rate declines at the peak of the spawning season.展开更多
基金Supported by the Faculty of Sciences of Sfax,Tunisia
文摘Objective:To present the first information on the feeding habits of the Mediterranean needlefish Tylosurus acus imperialis(T.a.imperialis)of Tunisia and to examine the diet variation in relation to the fish size,maturity and sex.Methods:Gut contents of 92 specimens of T.a.imperialis,collected mainly from May 2004 to July 2006 off the Gulf of Gabès,Southeastern Tunisian coast,were analyzed.Results:The results showed that 55.4%of them had empty guts and 44.6%contained food in their guts.The emptiness index did not vary significantly according to size classes or sexes of T.a.imperialis.Basic food consisted of teleosts(Mugilidae,Gobidae and Belonidae)(59.63%)followed by crustaceans(40.24%),mostly decapods Sycionia carinata(5.42%).A decrease in the feeding rate at the peak of the spawning season was observed for both sexes.A diet variation among juvenile and adult specimens of T.a.imperialis was found.Conclusions:This study enhances our knowledge on the biology of the Mediterranean needlefish T.a.imperialis.This fish is an active predator and an opportunistic feeder but the feeding rate declines at the peak of the spawning season.
