Use of Multivariate Analysis to Assess the Nutritional Condition of Fish Larvae From Nucleic Acids and Protein Content

• Main Authors: Cunha, Isabel, Saborido-Rey, Fran, Planas, Miguel
• Format: Article in Journal/Newspaper
• Language: English
• Published: Marine Biological Laboratory 2003
• Subjects: Turbot larvae; Scophthalmus maximus; Nutritional condition; Multivariate analysis; Input variables; Developmental stage; Turbot
• Online Access: http://hdl.handle.net/10261/9443

11 pages, 3 figures.-- PMID: 12807710 [PubMed]. The nutritional condition of turbot larvae (Scophthalmus maximus) was assessed by a multivariate analysis with DNA, RNA, and protein content as input variables. Special attention was given to the time that feeding began and to the timing and duration of starvation. The combination of the principal components analysis and the stepwise discriminant analysis, both techniques of multivariate analysis, made it possible to allocate the larvae into groups that were defined and identified based on similarities in developmental stage and nutritional condition. The developmental stage was mostly determined by the input variables DNA and protein content, while nutritional condition was determined by the RNA content. In the period studied, the more developed larvae were less resistant to starvation. Furthermore, when initial feeding was delayed as little as 6 h, the variables analyzed were markedly changed, and the effect on the deprived larvae was found to be equivalent to a 3-day delay in development - when compared with the larvae fed immediately after mouth opening. Through this technique, new samples of larvae with unknown history might be classified into groups, using their DNA, RNA, and protein content as input values in the defined classification functions. Results were compared to those obtained using RNA/DNA and RNA/dry weight indices, and the multivariate method was considered to be more sensitive and to provide extra information about larval nutritional history and development. This study was financially supported by the Comisión Interministerial de Ciencia y Tecnología (CICYT, Spain) under Project AGF 185/92. I. Cunha was supported by a postgraduate scholarship (BD/3489/94) from FCT (Portugal). Peer reviewed