New records of the invasive amphipod Echinogammarus ischnus (Stebbing, 1899) in Croatia

Abstract

The Ponto-Caspian alien and invasive amphipod, Echinogammarus ischnus (Stebbing, 1899), was found in Croatia at three sites in the lower course of the Drava River and at three sites in the Danube River (Batina, Borovo and Ilok). The most upstream site in the Drava where the species was found is a locality near Donji Miholjac, approximately 82 km upstream from the confluence with the Danube River. At this site as well as at two downstream sites (Osijek and Belišće) in Drava it was found together with the dominant invasive amphipods Dikerogammarus villosus and Chelicorophium curvispinum, while at the Donji Miholjac site it also co-occurs with two native species, Gammarus fossarum and G. roeseli. Ponto-kaspijski strani i invazivni rakušac Echinogammarus ischnus (Stebbing, 1899), pronađen je u Hrvatskoj u donjem toku rijeke Drave i na tri lokaliteta u Dunavu (Batina, Borovo i Ilok). Najuzvodnija postaja na kojoj je nađen u Dravi, kod mjesta Donji Miholjac, udaljena je otprilike 82 km od ušća u Dunav. Na toj, kao i na dvije nizvodne postaje (Osijek i Belišće) u Dravi, zabilježen je zajedno s druge dvije invazivne vrste rakušaca Dikerogammarus villosus i Chelicorophium curvispinum, dok na postaji kod Donjeg Miholjca uz ove dvije dominantne strane vrste dolazi zajedno s još dvije autohtone vrste Gammarus fossarum i G. roeseli.