The effect of using two-year-old male coho salmon in hatchery broodstock on adult returns

摘要

We conducted an experiment comparing the age at maturity of hatchery coho salmon Oncorhynchus kisutch sired with 2% or 100% age-2 jacks and released at two smolt sizes. Progeny sired by 100% age-2 males returned significantly more age-2 jacks than did those sired with 2% age-2 males. However. the survival and mean length of age-3 fish was similar for the two groups. Significantly more age-2 returns were produced by releasing larger (34-40 g) smolts rather than smaller (23-28 g) ones, but smolt size did not affect the Survival or mean length of age-3 returns.