Evaluation of egg quality in broodstock cobia Rachycentron canadum L.
Article first published online: 12 APR 2011
© 2011 Blackwell Publishing Ltd
Volume 43, Issue 3, pages 371–385, February 2012
How to Cite
Nguyen, H. Q., Reinertsen, H., Rustad, T., Tran, T. M. and Kjørsvik, E. (2012), Evaluation of egg quality in broodstock cobia Rachycentron canadum L. Aquaculture Research, 43: 371–385. doi: 10.1111/j.1365-2109.2011.02840.x
- Issue published online: 3 FEB 2012
- Article first published online: 12 APR 2011
- fish egg;
- egg quality;
- egg biochemical composition;
Twenty egg batches spawned naturally from 17 different females over two spawning seasons were used to evaluate the egg quality of cobia Rachycentron canadum. A reduction in egg size was observed towards the end of the spawning season for both years. The proportion of floating eggs demonstrated a positive linear relationship with both yolk-sac larval survival (r2=0.91, P<0.05) and batch larval production (r2=0.80, P<0.01). Viable egg batches (i.e. fertilization success >50%) were of higher batch fecundity, had larger eggs and a higher proportion of floating eggs than non-viable batches (i.e. 0% fertilization success). Also, biochemical analyses revealed that these viable eggs had significantly higher protein and amino acid contents. A multiple regression model based on the proportion of floating eggs, batch fecundity and fertilization success provided the most accurate predictions of batch larval production (r2=0.95, P<0.001). Similarly, using the egg content of arginine/glycine and methionine significantly increased the correlation coefficient in the multiple regression model predicting larval deformity (r2=0.92, P=0.002). This study reveals that accurate determination of egg quality in cobia can be improved using a combination of several variables rather than a single variable.