FRESH-WATER PERFORMANCE OF TRIPLOID ATLANTIC SALMON (SALMO-SALAR) IN NEW-BRUNSWICK AQUACULTURE

The use of ploidy manipulation to produce sterile salmon has been inve stigated since the mid-1970s. Today, the techniques for producing trip loids are well documented. In this study pressure shock techniques wer e employed to produce triploid Atlantic salmon on a commercial scale, and performance differences between triploids and diploids were assess ed. A new 2.5 1 pressure vessel was designed and used to produce appro ximately 36 000 triploid salmon during the 1992 spawning season. This vessel was highly successful in inducing triploidy, as determined by f low cytometry, Performance was based on survival and growth, which wer e monitored from the egg stage until the time of smelting, There were no significant differences in cumulative survival throughout the exper iment. During April, May and June of 1993, triploids were significantl y smaller than their diploid counterparts (P < 0.05), However, from Ju ly 1993 until February 1994 there were no differences in size. In Febr uary 1994 the smelting rate was determined by classifying those fish g reater than 13 cm as smelt. The success rates were 86% and 88% for tri ploids and diploids, respectively.