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Key-words:alien species, goby fish, parasite community, Vistula River A parasitological study of Ponto-Caspian gobies, including the monkey goby Neogobius fluviatilis, racer goby Babka gymnotrachelus and tubenose goby Proterorhinus semilunaris, carried out over four years in the lower Vistula River is described. These fish species represent one of the most impressive invasions of European inland waters, connected with the spontaneous, east-to-west intracontinental movement observed in the last two decades. The parasite community consisted of 24 taxa. Typical for racer goby were: Trichodina domerguei, Diplostomum pseudospathaceum, Gyrodactylus proterorhini and glochidia of unionids. The list of parasites typical for monkey goby is supplemented with: Tylodelphys clavata (met.) and Eimeria sp., while the glochidia were rarely detected in this fish host. Holostephanus spp., Apatemon gracilis, Diplostomum gobiorum and glochidia predominated in parasite fauna of tubenose goby. Unlike the other species tested, P. semilunaris was poorly infected with T. domerguei and G. proterorhini. Parasites commonly distributed through native fishes in the observed area prevailed in gobies. Species rare in natives were also numerously represented. In this way, alien fish reinforce populations of those parasites in invaded waters. Parasites dragged to the colonized area (G. proterorhini, Holostephanus spp., A. gracilis and D. gobiorum) complement the community. Larval stages were typical for parasite fauna of all studied gobies. RÉSUMÉParasites des gobies non indigènes dans le réservoir Włocławek sur la partie inférieure du fleuve Vistule, première étude exhaustive en Pologne Mots-clés :

A method for the mass marking of ide Leuciscus idus larvae by feeding them Artemia salina nauplii that were immersed in different solutions of alizarin red S, tetracycline hydrochloride and calcein was tested. The best quality marks were obtained after feeding fish for 4 days with nauplii that had been immersed in 200 mg l(-1) alizarin red S.

SummarySubject and purpose of work: The article presents the results of a study which aimed to elicit the opinions of the residents of Polish cities belonging to the Cittaslow Network.Materials and methods: The surveys were conducted among 100 residents from 10 Polish Cittaslow cities.Results: Most of the respondents did not identify the city’s accession to the Cittaslow with the improvement of the quality of their lives. The residents’ opinions concerning the changes that occurred after joining the Network depended on their gender, age and education.Conclusions: The survey results have revealed that the membership of the Cittaslow is strictly promotional. Its main objective is to raise funds from projects that promote the idea of Cittaslow as well as to get a promotion by participating in various international events. The opinions of the inhabitants of Cittaslow cities indicate the lack of significant effects established in relevant documents and strategies.

ABSTRACT:The aim of the experiment was to determine the effect of graded lipid content in experimental isoprotein feed (6, 10, 14% lipids and 45% protein) on the growth performance of juvenile pikeperch (initial body weight ≈ 210 g) in a recirculation system. No significant effect of the applied feed on the final average body weight was observed. However, average daily weight gain (g/d), SGR index (%/d) and condition coefficient of the fish receiving 10% lipid feed were significantly higher than the corresponding values in the other two groups (6 and 14% lipid, P < 0.05). Feed conversion ratio (FCR) and protein efficiency ratio (PER) a�ained the most advantageous values in this group of fish. The application of the experimental feed had a significant effect on the lipid values in fish bodies and viscera (P < 0.05) although no relationship was detected between the lipid content of the feed and that of the fish muscles. The lipid content was approximately 7.7% in all the experimental groups and the differences between the groups were statistically insignificant (P > 0.05).