| The purpose of this research was to: 1) determine an optimal protocol to produce triploid Atlantic cod using hydrostatic pressure, 2) examine gonadal development of adult-aged, triploid cod prior to and during the annual spawning season, and 3) assess the spawning potential of triploid males through a number of in vitro and in vivo experiments. Pressure treatments of 8500 psi applied for 5 min at 30 and 40 min post-fertilization had a 100% triploidy induction success. Female triploid Atlantic cod exhibited diminished ovarian development at both macroscopic and microscopic levels but testicular development was indistinguishable between diploid and triploid males. Triploid males were as successful at siring young in competition with size-matched diploid males. Spermatozoa produced by triploids were larger, but did not differ in swimming velocity or ability to fertilize eggs. Hatch and larval survival rates were reduced for progeny sired by triploid males. Therefore, diminished ovarian development and the inability to reproduce makes triploid females a candidate for commercial scale culture. |
