The Lumpfish (Cyclopterus lumpus) is the most widely used cleanerfish in Atlantic Salmon aquaculture. To ensure sustainability, reliable captive broodstock management is required however many aspects are still unknown. The sustainable captive production of lumpfish is reliant on good egg quality from captive broodstock. A key component in closing the life cycle of any species is improving survival within the egg. Thus, determining the components that affect egg quality is a key step in improving the sustainability of any captive breeding program. At present all production is currently being met by wild caught eggs, which is unsustainable moving forward and opens up the species for genetic selection for desirable traits.
The present study assessed the compositional changes of fatty acids, minerals, and pigments in wild lumpfish eggs over the course of embryonic development in order to identify potential egg quality determinants. Samples were taken at 6 different time points, stripping, 24 hours post fertilisation (8DD), 60, 150, 200-degree days and hatched larvae (350DD). There was a significant decrease in levels of total Monosaturates, Saturates, Total N-3 and N-6 PUFAS over the course of embryonic development. However, changes in levels of specific FFA’s varied. Levels of DHA and EPA decreased significantly between striping and hatching. 18:4 N-3 and 20:4 N-3 also decreased significantly between stripping, early development and hatching.
Levels of sodium, magnesium and a number of minerals increased over development suggesting import into the egg over the developmental process. As was as a number of changes throughout the developmental progress in mineral content. These findings suggest that some minerals may not be as a limiting factor in embryonic development for this species. Lumpfish eggs are well known for their diversity in egg colourations. With significant increases of Beta Carotene, as well as significant decreases in Canthaxanthin and astacene between stripping a hatch. Suggesting total pigment, not individual pigments being factors in egg quality for lumpfish
The present study sought to further address the issue of egg quality in Lumpfish. Currently underperforming eggs are a substantial limitation in the creation of a commercially viable broodstock. Areas of significant changes over development suggest potential egg quality determinates in lumpfish as well as an important bassline in further egg quality work within the species. This work can practically provide key information to inform the creation of broodstock diets for lumpfish, working to improve egg and juvenile quality to ultimately close the life cycle of this species.