Growth and First Maturation of Salmo salar m. sebago Introduced in Fish Farm "Nishava”

E. UZUNOVA1, K. YOROV2 and B. VELKOV3
1 Sofia University, Department of Hydrobiology and Ichthyology, BG-1241 Sofia, Bulgaria
2 Consultative Bureau of Provimi, BG-1241 Sofia, Bulgaria
3 Bulgarian Academy of Sciences, Institute of Zoology, BG-1000 Sofia, Bulgaria

Abstract

UZUNOVA, E., K. YOROV and B. VELKOV, 2002. Growth and first maturation of Salmo salar m. sebago introduced in fish farm “Nishava”. Bulg. J. Agric. Sci., 8: 629–633

During the four-years growing period in “Nishava” fish farm, landlocked salmons (Salmo salar m.sebago) achieved average weight of 690.7±36.2 g and average length of 385.1±23.2 mm. The corresponding values of the rainbow trout reared in the same farm were 1081.1±189.97 g and 456.2±21.9 mm. During the first two years of breading, the landlocked salmons from native area lag behind the ones bred in “Nishava” fish farm. At the end of four year the native salmon population overgrow significantly those bred in Bulgarian fish farm. Possible reasons for this faster growth rate of Maine “wild” salmons during their third and four years was probably based on their removing from streams to lakes with abundance of live food. During the autumn of four year, 100% of males and 30% of females reached sexual maturity. The values of average eggs diameter – 5.97±0.08 and absolute fecundity – 327±78.6 of salmon bred in “Nishava” fish farm. On the basis of the data obtained through the four-years period following the development of Salmo salar m.sebago bred in “Nishava” fish farm we may conclude that landlocked salmon is a species suitable for extensive and semi-extensive breeding in Bulgarian lakes, reservoirs and fish farms.

Key words: Salmo salar m. sebago, aquaculture, fish farm