amino acid profiles in sparus aurata larvae under dif

LARVI ’09 – FISH & SHELLFISH LARVICULTURE SYMPOSIUM C.I. Hendry, G. Van Stappen, M. Wille and P. Sorgeloos (Eds) European Aquaculture Society, Special Publication No. 38, Oostende, Belgium, 2009

AMINO ACID PROFILES IN SPARUS AURATA LARVAE UNDER DIFFERENT FEEDING CONDITIONS – TESTING VEGETABLE PROTEIN SOURCES IN MICRODIETS M. Yúfera1, M. Alaiz2, F.J. Moyano3, P. Pousão-Ferreira4, M.M. Yust2, F. Millán2, and J.J. Pedroche2 1 2 3 4

Instituto de Ciencias Marinas de Andalucía (CSIC), Apartado Oficial, E-11510 Puerto Real, Spain Instituto de la Grasa (CSIC), Av. Padre García Tejero 4, E-41012 Sevilla, Spain Dept. Biología Aplicada. EPS, Universidad de Almería, E-04120 Almería, Spain INIP/CRIPA, Av. 5 de Outubro, s/n, P-8700 Olhão, Portugal

Introduction Proteins of vegetable origin are products offering a certain variety in the amino acid profile depending on the species and may be an interesting ingredient in larval diet formulation. Having this in mind, variations in total amino acid (AA) profiles related to different feeding conditions (live prey, microdiets and starved) were measured in early Sparus aurata larvae obtained from different spawns collected during two years. A first objective of the present work was to assess to what extent changes in feed quantity would be reflected in the amino acid profile of larvae. A second objective was to use such information as a reference for a further nutritional evaluation of microdiets which included a certain proportion of vegetable protein hydrolysates. Results were compared to previously published amino acid profiles in this species, in order to assess their potential variability. Material and methods Larvae were reared in 300-l tanks at 19.5ºC and 35g.l-1 and fed rotifers (Brachionus rotunduformis and B. plicatilis) and Artemia nauplii according to standard protocols. Determinations were carried out at different developmental stages on larvae either fed on live food or experimental microdiets, as well as on starved individuals. Whole-body amino acid content on larval pools were analysed by reversed-phase HPLC using D,L-α aminobutyric as internal standards (Alaiz et al., 2004). Microdiets were prepared according to Yúfera et al. (2005). The microdiets differed in the source of fish and vegetable hydrolysates (CPSP90, rapeseed, sunflower and chickpea) used in their formulation. All diets were prepared with 27.5% fish meal, 30% of cuttlefish meal and 10% of protein hy-

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drolysate on weight basis. Only particles with a diameter ranging between 80 and 200µm were considered in the present study. Results and discussion Changes in the AA profiles in rotifer fed larvae are shown in Figure 1. The general trends observed during embryo and growing phases were different. Threonine, isoleucine, leucine, serine, and alanine decreased during the endogenous feeding period, while glycine, asparagine + aspartic acid, and glutamine + glutamic acid increased. Lysine and cysteine showed small variations during the whole considered period. The day of first feeding is clearly discernible with the noticeable change in the content of some AA (methionine, valine, tyrosine, and asparagine + aspartic acid). 10

12

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10 8

% AA

6

6

4 4

2 0

2

Met

His

Thr

Phe

Arg

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Ile

Val

Lys

Leu

18

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% AA

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6

10 8

4

6 4

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Tyr

Pro

Ser

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Gly

Ala

Asp+Asn Glu+Gln

Fig. 1. Total amino acid profiles during embryo and larval development of Sparus aurata fed on live prey. Each bar group indicates the values at 0, 1, 2, 3, 4, 6, 9, 11, and 15 DAH consecutively.

On the other hand, unfed larvae after the mouth opening showed significant increase in glycine and decrease in isoleucine, leucine, threonine, and valine. This result indicates that larvae need to use also essential AA as metabolic fuel during this short period from mouth opening up to 9DAH. No significant changes were observed in other AA. Significant differences between profiles in fed and unfed larvae (ANCOVA; p