Growing results of arctic char juveniles (Salvelinus alpinus L., 1758) in a weakly saline artificial medium

The purpose of this work is to increase the rate of development and growth of Arctic char juveniles, a valuable promising specy for both commercial cultivation and artificial reproduction. The basis of the new method of the increasing cultivation biotech efficiency is the use the artificially saline biostimulating medium. For maximum stimulation of the juveniles growth rate, they were grown at a commercial farm in table salt solutions of 0.5–1.5‰ concentration, where 2 most important and widely used factors of the same effect were additionally included — optimal temperature and planting density, according to the basic principle of the natural impacts complexity. The maximum weight values (428±23 g) were obtained in a group with pre-sorted leaders of the lowest planting density (27 pd/m3) with that compared to more compacted (119±15 g) and control in fresh water (93.8±0.52 g) both in the same planting density (500 pd/m3). For the first time, an increase in the growth rate of Arctic char juveniles was observed when using even a slightly saline medium (0.5–1.5‰), below the threshold of critical salinity (4–8‰). The main advantage of growing juveniles in this combined medium — the growth rate increase to 26.97% was revealed, by comparative analysis. The industrial table salt solutions of low concentration are proposed to use in combination with known methods for optimizing the juveniles planting density (as well as temperature regimes, sorting) to accelerate the growth rate of juveniles that comparable to the effect of critical salinity in closed water supply systems of fish farms for yearround rearing.