CALIFORNIA YELLOWTAIL Seriola lalandi EGG QUALITY AND CHEMICAL COMPOSITION  

The production of poor or inconsistent quality eggs in marine finfish culture is a limiting step in the development of hatchery techniques for reliable juvenile production. Efforts to optimize egg quality require a greater understanding of the underlying factors influencing egg quality.  To this end, we investigated intrinsic chemical properties (proximate composition and fatty acids) of eggs from tank-spawning California Yellowtail (CYT) in conjunction with egg and larval characteristics generally considered to be related to quality.  

CYT eggs from captive wild and F1 broodstock spawning events were collected in 2013, while only eggs from wild brood were available for collection in 2014. A spawn was categorized as good or poor quality when the volume of viable (positively buoyant) eggs was ≥70% or ≤30%, respectively.  A total of 48 egg samples representing good or poor quality spawns from each brood type were analyzed from 2013.

While egg proximate composition was neither correlated to egg quality nor brood type, fatty acid composition was well correlated with brood type, and to a lesser extent, egg quality. Canonical discrimination analysis of egg fatty acids (Figure 1) graphically separated egg samples by brood (symbol shape) and somewhat by quality (symbol fill). Regression analysis additionally identified a number of linear relationships between egg fatty acids and egg quality indices among 2013 eggs that we will further examine with 2014 eggs.