Parasites ofApollonia melanostoma(Pallas 1814) andNeogobius kessleri(Guenther 1861) (Osteichthyes, Gobiidae) from the Danube River in Austria

Abstract

Two invasive fish species, the round goby Apollonia melanostoma syn. Neogobius melanostomus (Pallas 1814) and the bighead goby Neogobius kessleri (Günther, 1861), have established a firm population in Austrian waters during the past 15 years. As there have been no records of the parasite fauna from these populations, a total of 79 specimens of A. melanostoma and 12 specimens of N. kessleri were examined for parasites between May and October 2007 from three different sampling sites from the Danube River in Austria. In total 12 parasite taxa were recovered. The protozoans Trichodina sp. and Ichthyophthirius multifiliis from the gills and skin; two crustacean species, Paraergasilus brevidigitus and Ergasilus sieboldi, from the gills; and the two monogeneans Gyrodactylus sp. and Dactylogyrus sp., from the skin and gills respectively, all occurred at low prevalence and intensities. Furthermore, cystacanths of the acanthocephalan Acanthocephalus lucii were found in the body cavity. Metacercariae of the digeneans Diplostomum sp. and Tylodelphys clavata were found in the lens of the eye and the vitreous humour, respectively. Adults of two digeneans, Nicolla skrjabini and Bunodera nodulosa, were found in the intestine. In addition, during this survey metacercariae of the Holarctic digenean Bucephalus polymorphus, encysted in the skin and fins, with prevalence up to 78%, were recorded for the first time in Austria.

The colonization of the invasive round goby Neogobius melanostomus by parasites in new localities in the southwestern Baltic Sea

“…The processes of colonization of the invasive round goby by parasites in the Baltic Sea and the Great Lakes support the "enemy release hypothesis". Opposite to these processes, in the Danube basin, the invasive round goby introduced the digenean Bucephalus polymorphus following the invasion of the first intermediate host Dreissena polymorpha into mid-European waters (Mühlegger et al 2009(Mühlegger et al , 2010. The parasite fauna of the round goby from the Gulf of Gdańsk is characterized by low similarity with one from the Black Sea.…”

Parasite fauna of native and non-native populations of Neogobius melanostomus (Pallas, 1814) (Gobiidae) in the longitudinal profile of the Danube River

“…(2005) in the Slovak section of the river (metazoan parasites). Further, protozoan and metazoan parasites of round goby were investigated in Hungarian (Molnár, 2006) and Austrian (Mühlegger et al., 2010) sections of the Danube River. Round gobies were found to be infected with a total of 15 metazoan parasite species at those three sites.…”

Non-native gobies facilitate the transmission of Bucephalus polymorphus (Trematoda)

“…Recent dispersal of B. polymorphus in some European waters has been attributed partly to expansion of the first intermediate host, the zebra mussel Dreissena polymorpha , and partly to expansion of Ponto-Caspian gobies serving as second intermediate hosts [ 19 , 20 ]. Although D. polymorpha has been present in the River Morava basin for more than 40 years [ 37 ], a marked increase in B. polymorphus abundance was observed only several years after the introduction of the tubenose goby [ 38 ].…”

“…The occurrence of B. polymorphus in the River Morava basin was first recorded in the 1950s, from both intermediate (mainly cyprinid) and definitive (mainly percid and esocid) fish hosts (summarized in [ 18 ]). High susceptibility of Ponto-Caspian gobies to B. polymorphus in their non-native range has recently been reported from the middle Danube [ 19 ] and River Vistula [ 20 ]. Although this parasite is known to use some goby species as intermediate hosts in the Black Sea basin in estuaries [ 21 ], infection is rare [ 22 ].…”