Relationship between standard metabolic rate and parasite-induced cataract of juveniles in three Atlantic salmon stocks
Abstract:The connection between standard metabolic rate (RS) and parasite-induced cataract was investigated in this study. Oxygen consumption rate and cataract of 1 year-old fish in three Atlantic salmon Salmo salar stocks: Lake Saimaa, River Neva and River Teno reared at the same fish farm were examined. The measurements were carried out in winter, in spring before transporting the fish to the outside raceways and in autumn after the raceway period. Fish were exposed to natural Diplostomum spp. infection especially during the raceway period. The prevalence of cataract-bearing fish and cataract intensities (IC) differed between the populations. Most cataract-bearing individuals were found in the Saimaa stock and, in addition, the Saimaa stock had higher IC than Neva and Teno stocks. These findings support the theory of a parasite being most infective to local population. The RS, however, differed also between the stocks, the Teno stock had higher values compared to the Neva stock in winter. Furthermore, RS and cataract intensity had a statistically significant positive correlation in autumn. Therefore, the results also reveal a possibility that parasite infection affects RS of the fish.
Document Type: Regular Paper
Publication date: May 1, 2008