Infection of the swim bladder parasite Anguillicoloides crassus in the European eel (Anguilla anguilla) caught from the Gediz Delta (Aegean Sea)

Abstract

The wild European eels (776 fish, mean total length of 547±91 mm, mean weight 340±198 g) were obtained monthly between October 2015-September 2016 in Gediz Delta (Izmir Bay, Aegean Sea). A total of 263 nematode parasites (Anguillicoloides crassus) were isolated from the swim bladders of 52 parasitized fish. Parasitological indices were found relatively low. The prevalence was 6.7% and the mean intensity was 5.05. The abundance of A. crassus was also calculated as 0.33 in all sampled eels.

Composition and variations diet of the European eel Anguilla anguilla (Linnaeus, 1758) in Tonga Lake, North-East Algeria.

“…Globally, scientific advice confirms that the situation of eels at all stages of their development stages remains critical throughout their range. This decline was favored to barriers to up-and downstream migration (including damming of river systems for hydro-electric power), damming of river systems for hydro-electric power), toxicogenetic damage by anthropogenic pollutants (Belpaire et al 2019;Turan et al 2020), natural diseases, such as viral infections (Bandin et al 2014;McConville et al 2018) and the parasitic alien nematode Anguillicola crassus (Kantzoura et al 2021;Gürkan et al 2022;Salman 2023) but also to poaching and smuggling activities (illegal, unreported and unregulated 2 fishing, illegal trade) (Musing et al 2018;Alonso and van Uhm 2023). Indeed, during the fishing season 2018-2019, EUROPOL seized over 5 tons of smuggled glass eels with an estimated value of € 2000 per kilo under the European Union Action Plan against wildlife trafficking (https://www.europol.europa.eu/).…”