Bucephalus polymorphus Baer, 1827 - a new fish parasite in Austria?

Area of Science:

• Ichthyoparasitology
• Invasive Species Biology
• Freshwater Ecology

Background:

• The round goby (Apollonia melanostoma) is an invasive fish species found in the Danube River.
• The digenean parasite Bucephalus polymorphus has a life cycle dependent on the zebra mussel (Dreissena polymorpha) as an intermediate host.
• Both the round goby and zebra mussel are invasive species in Austrian waters.

Purpose of the Study:

• To report the first detection of Bucephalus polymorpha in Austria.
• To document the presence of parasite metacercariae in the round goby.
• To investigate the potential establishment and impact of this parasite on native fish populations.

Main Methods:

• Parasitological examination of invasive round goby (Apollonia melanostoma) from the Danube River.
• Identification of digenean parasite metacercariae.
• Literature review on the distribution of intermediate hosts (Dreissena polymorpha).

Main Results:

• Encysted metacercariae of Bucephalus polymorpha were identified on the fins, skin, and gills of Apollonia melanostoma.
• The first occurrence of Bucephalus polymorpha in Austria was recorded in 2007.
• The presence of the parasite is linked to the invasive zebra mussel, Dreissena polymorpha, which has been established in Austria since 1870.

Conclusions:

• The introduction of Bucephalus polymorpha into Austria, via Apollonia melanostoma or other means, requires further investigation.
• Future studies should focus on the parasite's establishment potential and its impact on native Austrian fish communities.
• Monitoring the spread and ecological effects of invasive species and their associated parasites is crucial for aquatic ecosystem health.