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Fatty acid profiles of total, neutral, and polar lipids in the liver, muscle, and intestine of female individuals of Vimba vimba (L., 1758) were determined by gas chromatography. C16:0, C16:1 n-7, C18:1 n-7, and C18:1 n-9 were the most abundant fatty acids in total and neutral lipids in all tissues investigated. In addition to these acids, C20:4 n-6 (arachidonic acid) and C22:6 n-3 (docosahexaenoic acid) were the other fatty acids having high percentages in the polar lipid fraction of the tissues. The highest and lowest n-3 to n-6 ratios, which are a good indicator of the quality of fish oils, were determined in the muscle (1.68) and liver (0.68) in the polar lipid fraction, respectively. It was determined that the species had low levels of the n-3 forms of polyunsaturated fatty acids in the investigated tissues. For a better understanding of fatty acid metabolism of V. vimba, more detailed studies are required in terms of feeding experiments. [ABSTRACT FROM AUTHOR]

The seasonal changes of diet in the guts of 298 vimbas (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 (mollusks), fish larvae, macrophytes, oligochaetes, chironomids, phytoplankton, and detritus. The gut fullness index (GFI) indicated that vimbas increased their feeding activity in summer and decreased it in winter. The correlation between GFI and temperature was significant (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 (cluster analysis), while the highest similarity of diet composition was between adult individuals in autumn and winter (cluster analysis). In both size groups and in all seasons, the main food items were macrophytes, D. polymorpha, and phytoplankton (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. [ABSTRACT FROM AUTHOR]

The infestation by a relatively less known monogenean, Dactylogyrus cornu Linstow, 1878, was investigated on vimba, Vimba vimba tenella Nordmann, 1840 in a small stream pouring into the Black Sea in Sinop, Turkey. A total of 122 fish specimens were examined in June 2000. The overall infestation prevalence and mean intensity levels were 100% and 147.7 ± 7.9 parasites per infested fish, respectively. D. cornu was recorded only on the gills of host fish and possible site specificity to the filaments of the second gill arches of the left and right gill arch sets was recorded. The parasite was also found to be settled more on female and larger host fish. [ABSTRACT FROM AUTHOR]