标题：Preliminary study of dietary interactions between invading Ponto-Caspian gobies and some native fish species in the River Danube near Bratislava (Slovakia)
其他标题：Preliminary study of dietary interactions between invading Ponto-Caspian gobies and some native fish species in the River Danube near Bratislava (Slovakia)
摘要：Dietary breadth and diet overlap were examined in two native fish species (Eurasian perch Perca fluviatilis , Balon�s ruffe Gymnocephalus baloni ) and two invading species (round goby Neogobius melanostomus , bighead goby Neogobius kessleri ) in the Middle Danube (Slovakia) at dawn and dusk over two consecutive 24-h periods in late summer 2004. Dietary breadth was narrow in all species/age classes except perch of ages 4 and 5. Dietary overlap between native fishes and the invading gobies was very high, except for age 3 perch. This high overlap was due to a preference, high in some cases, for gammarids. Our preliminary results suggest the potential for competition between the invading and native fishes, which requires further study.
