Determination of different light intensity on yolk sac absorption of diploid and triploid Coruh trout (Salmo coruhensis) larvae

In this study, to determine growth rate, yolk conversion efficiency, dry weight and water content during the yolk absorption of diploid and triploid Coruh trout (Salmo coruhensis) under three different photoperiod regimes (N: Normal day period, 24hL: Continuous light, 24hD: Continuous darkness). Triploids were produced by heat shock and using 10-min heat shock 28 °C following 10-min post fertilization. At the end of the study, length and weight increase as well as growth rates, daily yolk sac consumption, yolk sac efficiency values and development index were calculated in diploids, normal day period 0,344 mm/day, 1,024 mg/day, 0,800 mg/day, 0,622 and 1,942, continuous light 0,314 mm/day, 0,921 mg/day, 0,785 mg/day, 0,603 and 2,078, continuous darkness 0,315 mm/day, 0,872 mg/day, 0,786 mg/day, 0,629 and 1,962; in triploids normal day period 0,321 mm/day, 1,234 mg/day, 0,844 mg/day, 0,624 and 1,992, continuous light 0,303 mm/day, 1,262 mg/day, 0,836 mg/day, 0,657 and 2,052, continuous darkness 0,320 mm/day, 0,849 mg/day, 0,845 mg/day, 0,584 and 1,928, respectively. Revealed the relationships between larval development and degree-days, dry body weight and dry matter of larvae increased, while dry yolk, total dry larval weights and water content decreased with degree-days.