Reproductive biology of lumpfish (Cyclopterus lumpus): a key to successful selective breeding

Abstract

A detailed description of lumpfish reproductive biology has been described in terms of gonadal development using histological analysis and physiology using sex steroid development. This knowledge of basic reproductive biology of lumpfish has adopted by our industry partners in their breeding activities in their facilities. Our results demonstrated that spawning of lumpfish can be shifted using photomanipulation to spawn different times of the year and spawning can also be synchronized by increasing the temperature prior to ovulation. This means that lumpfish broodstock can be photomanipulated to spawn different times of the year. Compressing the natural photoperiod resulted in temporal shifts in levels of sex steroids and advanced gonad development, leading to earlier spawning. This knowledge has been currently implemented by our industry partners AquaGen and Namdal Rensefisk. Further, a non-invasive method for gender identification of lumpfish at smaller size (less than 50 g) using ultrasound technology has been developed in Cyclobreed project and the accuracy of this method is more than 90%. This is a huge benefit and important tool for the breeding companies, in this case our industrial partner AquaGen, in maintaining a proper sex ratio (increased females) in their breeding program. Currently AquaGen has implemented this tool in their breeding program for lumpfish.