After a successful week of electrofishing in Bråån and Tommarpsån four weeks ago, Laura and I started to prepare an aquaria room at Lunds University for an initial fish-infestation experiment. Cleaning aquaria, buying and arranging equipment or settling up oxygen-pipes were some of our tasks for the week.
This let us continue with a second successful electrofishing-action with Niklas afterwards. With a car full of fish many different species were transported from Klingavälsån and Fyleån to the aquaria room in Lund at several chargings. Four different fish species were caught in Fyleån, ten in Klingavälsån directly at Hemmerstorps Mölla. What a positive surprise! Bullheads (Cottus gobio) and three-spined sticklebacks (Gasterosteus aculeatus) occurred in both streams, brown trout (Salmo trutta) and minnow (Phoxinus phoxinus) in Fyleån. Roach (Rutilus rutilus), silver bream (Abramis bjoerkna), perch (Perca fluviatilis), stone loach (Barbatula barbatula), common bleak (Alburnus alburnus), pike (Esox Lucius), tench (Tinca tinca) and nine-spined stickleback (Pungitus pungitus) were caught in Klingavälsån. The latter mentioned species were only a few individuals each, but still interesting for testing host-fish suitability. At the end of the week Niklas found 15 gravid mussels in Bråån which we finally transported to the lab.
Since bringing the animals in the aquaria room the tension has been increasing every new morning hoping that all fishes and mussels survived the night. A few bullheads died because of fungal infections, but the general situation is stable now. It was possible to count all fishes and to check their gills for ongoing infestation by mussel glochidia. This was a great balance between anesthetizing baths and fast but still thoroughly looking at the gills with further waking up baths. Between checking the mussels for glochidia release and regularly changing the water, fishes were fed and aquaria were cleaned. It was great to have Deplhine’s help during the week which made it possible to work effectively. Thanks a lot! Many fishes in a small and cold room bring along a lot of work. We now hope to get enough ripe glochidia for starting the experiment. If not, we’ll try with further mussels ;).