Triploid (sterile) farmed Atlantic salmon males attempt to spawn with wild females

Abstract

Genetic interaction between farmed escapees and wild conspecifics represents one of the major environmental challenges faced by the Atlantic salmon aquaculture industry. In order to mitigate genetic interactions, triploid (sterile) farmed fish can be produced. However, triploids may still develop secondary sexual characteristics, and potentially attempt to spawn with wild fish. Here, triploid farmed salmon males were placed into 2 spawning arenas containing either a wild and a farmed female, or a wild and a farmed female and wild males. Qualitative observations demonstrated that triploid male Atlantic salmon displayed the full range of spawning behaviors of wild males, and stimulated the wild female to spawn in the absence of wild males. Quantitative aspects of the observed behaviors, such as their frequency among triploid males and the competitive ability of farmed triploid males compared with diploid farmed and wild males, requires investigation before full-scale production of triploid salmon is initiated commercially.