NON-REPRODUCTIVE RAINBOW TROUT

NON-REPRODUCTIVE RAINBOW TROUT

Triploid or non-reproductive rainbow and brook trout have been used in the provincial stocking program for almost 20 years. The primary reasons for investing in and developing the triploid technology was for improving specific lake fisheries such as those managed for a quality fishing experience and to ensure the preservation of other native genetic stocks. Triploids are sterile and thus will not hybridize with native populations. Pennask and Blackwater rainbow trout are stocked as either diploids (reproductive) or triploids as dictated by the management regime for a particular lake. Fraser Valley rainbow trout are all released as triploid fish. FFSBC fish culturists have taken the triploid process one step further by developing all female triploid rainbow trout. As the name suggests, these are non-reproductive female trout so the stocking would not include any males. Triploid male trout develop secondary sexual maturation traits including bright spawning colouration and incomplete development of gonads. The triploid males cannot successfully spawn and there is mortality associated with the false sexual development. Stocking of all female triploids eliminates the potential loss of male trout from the fishery. The ideal stocking situation for consideration of triploid rainbows and all female triploids would be a highly productive, landlocked interior lake that has extensive shoal or shallow water feeding areas as well as a good mix of deep water habitat. This lake would be managed for quality fishing experiences and would have regulations such as a reduced or 0 limit, gear restrictions and a winter fishing closure. This scenario would allow the non-reproductive trout the best opportunity to grow to trophy size while still offering anglers a chance to catch and release these fish.