|Rawles, Steven - Steve|
Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract only
Publication Acceptance Date: 2/4/2007
Publication Date: 2/26/2007
Citation: Rawles, S.D., Ludwig, G.M., Lochmann, S., Gaylord, T.G. 2007. The effect of rotifer enrichment strategy on sunshine bass larvae fatty acid profile [abstract]. Book of Abstracts Aquaculture America. p. 754. Interpretive Summary:
Technical Abstract: We previously reported that larval hybrid striped bass subjected to different fatty acid enrichments showed little differences in morphometric characters or survival. In this study we investigated the influence of enrichment fatty acid composition on that of the larval fish. A canonical discriminant analysis (CDA) was conducted of fatty acid concentrations in hybrid striped bass fry which had been fed rotifers enriched with various combinations of two commercial emulsions (Culture Celco 3000®, C; Super Celco, S) and two algal pastes (Nannochlorpsis, N; Pavlova, P). The fry foods included rotifers fed N (Rn), rotifers fed N and C (Rnc); rotifers fed N, C, and S (Rncs), and rotifers fed N, C, and P (Rncp). Fatty acid profiles were significantly different (Wilks’-Lambda < 0.0001) among treatments and three canonical variates (CAN1-3) accounted for 83% of the variance. CAN1 with respect to CAN2 maximally separated fatty acid profiles of enrichments vs. rotifers vs. fry; whereas, CAN2 maximally separated profiles within each treatment type, e.g., rotifers fed different enrichment combinations (Fig. 1). CAN3 accounted for 10% of the variance and CAN 1 vs. CAN3 (not shown) maximally separated initial unfed fry (Fi) from fed fry based predominantly on higher levels of 16:1, 18:3, 22:5 and 22:6 and lower levels of 20:5 as well as the saturates 14:0, 16:0, and 18:0 as indicated by CAN3 canonical coefficients. The wider spread along CAN2 with respect to CAN1 among rotifers receiving different enrichments contrasts with tighter grouping of fry receiving different rotifers and suggests dilution of enrichment strategy up the food chain. Closer examination of canonical coefficients for each variate (data not shown) reveals differences in fatty acid composition among treatments. For example, the coefficients with respect to CAN1 indicate algal pastes were higher in 14:0, 14:1, 20:0, 20:1 and 22:5 and lower in 18-C fatty acids and 22:6 than commercial emulsions. Within rotifers, tight grouping of Rn and Rnc in closer proximity to N than C indicates the addition of Culture Selco® had little influence on final rotifer fatty acid profile. In contrast, the distinct separation and progressively negative locations of Rncp and Rncs® with respect to Rn and Rnc reflects greater influence of Pavlova and Super Selco fatty acid compositions as a result of greater n-3 content, i.e., negative CAN2 canonical coefficients for 18:3, 20:5, 22:5, and 22:6. Finally, CDA indicates little differences in the fatty acid profiles of hybrid striped bass fry fed rotifers receiving the different enrichments and supports our previous observation that final performance measures did not differ among fry.