Effects of LHRHa treatments upon the timing of ovulation and upon egg and offspring quality in Arctic charr, Salvelinus alpinus (L.)

Abstract Five groups of Arctic charr, Salvelinus alpinus (L.), were studied, each group consisting of 13 females. The fish in four of the groups received a single intramuscular (IM) injection: three groups were injected with LHRHa in various forms and dosages, and one was injected with saline (control). The females in the fifth group were implanted with controlled‐diffusion implants containing LHRH analogue. Ovulation in two of the treatment groups (30μg/kg D‐Ala⁶ LHRH and 150μg/kg D‐Trp⁶ LHRH) occurred earlier, and was better synchronized, than in the control group. The treatments did not significantly affect (1) the weight of eggs released from each female; (2) egg size, weight, or chemical composition; (3) mortality rates; (4) hatching times or the length of alevins. The fertilization rate in one of the treatment groups (150 μg/kg D‐Trp⁶) was significantly lower than in the control group.