FEEDING ECOLOGY OF VENDACE, COREGONUS ALBULA (L.), IN LAKE WIGRY (NORTHEASTERN POLAND)
Tomasz K. Czarkowski*, Andrzej Martyniak*, Andrzej Kapusta**, Anna Wójcik*, Magdalena Bowszys***, Bogdan Wziątek*, Urszula Szamańska*, Jacek Kozłowski*
*Department of Fish Biology and Pisciculture, University of Warmia and Mazury in Olsztyn, Poland
**Department of Ichthyology, The Stanisław Sakowicz Inland Fisheries Institute in Olsztyn, Poland
***Department of Applied Ecology, University of Warmia and Mazury in Olsztyn, Poland
ABSTRACT. The aim of the study was to present selected issues concerning the feeding of adult vendace, Coregonus albula (L.) in Lake Wigry. Seasonal changes in dietary composition, feeding intensity, and vendace preferences for the most important prey taxa were determined. Fish were caught monthly from April to October in 2001 and 2002. The main food components were Cyclops vicinus and Daphnia spp. Significant seasonal variation in diet composition was confirmed in both study years. In spring and fall, this species fed on large copepods, particularly Cyclops vicinus, while in summer it consumed cladocerans, primarily Daphnia cucullata. Chaoborus sp. larvae and chrysalises were a substantial component of vendace food . The most intense feeding was noted in April and May, while the least intense was recorded in July and August. The highest percentage of fish with empty digestive tracts (40%) were confirmed in July, while in spring and fall prey was noted in the digestive tracts of all the individuals examined.
Key words: VENDACE, ZOOPLANKTON, FOOD, CYCLOPS VICINUS, LAKE WIGRY
Tomasz K. Czarkowski, Warmińsko-Mazurski Ośrodek Doradztwa Rolniczego, Dział Ekologii i Ochrony Środowiska, ul. Jagiellońska 91, 10-356 Olsztyn, Tel./Fax: +48 89 5357684; e-mail:email@example.com