Feeding ecology of vimba (Vimba vimba L., 1758) in terms of size groups and seasons in Lake Sapanca, northwestern Anatolia

Authors : Hacer Canan OKGERMAN, Cumhur Haldun YARDIMCI

Pages : 288-297

Doi:10.3906/sag-1302-16

View : 22 | Download : 10

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :The seasonal changes of diet in the guts of 298 vimbas insert ignore into journalissuearticles values(Vimba vimba L.); caught on a monthly basis in Lake Sapanca from August 2003 to July 2004 were analyzed. V. vimba fed on ostracods, gastropods, Dreissena polymorpha insert ignore into journalissuearticles values(mollusks);, fish larvae, macrophytes, oligochaetes, chironomids, phytoplankton, and detritus. The gut fullness index insert ignore into journalissuearticles values(GFI); indicated that vimbas increased their feeding activity in summer and decreased it in winter. The correlation between GFI and temperature was significant insert ignore into journalissuearticles values(0.839, P < 0.01);. The water temperature shift was one of the critical environmental factors affecting the feeding of vimbas in Lake Sapanca. The lowest similarity of diet composition was between the juvenile vimbas in autumn and the adult vimbas in spring insert ignore into journalissuearticles values(cluster analysis);, while the highest similarity of diet composition was between adult individuals in autumn and winter insert ignore into journalissuearticles values(cluster analysis);. In both size groups and in all seasons, the main food items were macrophytes, D. polymorpha, and phytoplankton insert ignore into journalissuearticles values(particularly bacillariophytes);. Of animal food items, adult individuals fed mostly on D. polymorpha, while ostracods were consumed only by juvenile fish in spring, summer, and autumn. The benthic-omnivorous strategy of vimba is demonstrated by the high abundance of plant foods in their guts, confirming this mixed type of diet.
Keywords : Key words Vimba, Vimba vimba L, feeding ecology, benthic omnivorous, Lake Sapanca