Fish oil and meal replacement in mullet (Mugil liza) diet with Spirulina (Arthrospira platensis) and linseed oil.

This research evaluated the effect of the simultaneous substitution of fish meal and fish oil at 0, 30, 50, 70 and 100% (termed SS0, SS30, SS50, SS70 and SS100, respectively) with both Spirulina (Arthrospira platensis) and linseed oil. The effect on growth, colour, fatty acid (FA) profile, and liver and muscle antioxidant response in mullets (Mugil liza) were evaluated. A full substitution was not possible due to a final body weight reduction (p < 0.05). The colorimetric analyses showed an improvement in fillet colouration (p < 0.05). Also, we found a saturation of carotenoids in muscle at 30% substitution. The content of highly unsaturated fatty acids - HUFA (DHA, EPA and ARA) in muscle diminished as the substitution level increased and, at the same time, the level of these FAs in the diet diminished. We found interesting evidence of elongation from 18:3n-3 to 20:3n-3 when substitution with linseed oil levels was above 50% but no desaturation to 20:4 or 20:5n-3 was found, which could insinuate a certain n-3 HUFA requirement under the experimental conditions. Moreover, we noted an increase in the antioxidant capacity up to the treatment SS70; the SS100 treatment showed a diminution in the antioxidant capacity. It is concluded that a partial inclusion of Spirulina and linseed oil (50%) is possible, and that this replacement can increase antioxidant responses, improve its growth performance and can modulate the mullets fillet quality without affecting negatively fillet fatty acid content.

Description of amino acid and fatty acid content during initial development of Lophiosilurus alexandri (Siluriformes: Pseudopimelodidae), a carnivorous freshwater catfish

Samples of eggs, newly hatched larvae (NHL), and larvae at the end of the lecithotrophic period (eight days after hatching) (LPL) of Lophiosilurus alexandri were collected to determine the amino acid and fatty acid profiles. Crude protein did not change throughout initial development and the concentration of lipids was highest in NHL. The content of the indispensable amino acids (IAA) isoleucine, leucine, and valine decreased in LPL, while in eggs and NHL they remained high and similar in value. The dispensable amino acids (DAA), such as aspartic acid, tyrosine, and glycine, increased in LPL, while alanine decreased. The percentage of neutral lipids increased in LPL. The saturated fatty acid content decreased during ontogeny, while monounsaturated fatty acids decreased only in LPL. The polyunsaturated fatty acid content was highest in LP. Polar fatty acids were found in higher percentages in eggs and NHL, but lower in LPL. Saturated fatty acid content decreased during ontogenetic development, while that of monounsaturated fatty acids decreased only in LPL. Polyunsaturated fatty acid content was highest in LPL. Protein content was maintained during ontogenetic development, while amino acid classes experienced changes. Lophiosilurus alexandri preferentially uses saturated and monosaturated fatty acids as an energy source during its early development.(AU)

Amostras de ovos, larvas recém-eclodidas (NHL) e larvas no final do período lecitotrófico (oito dias após a incubação) (LPL) de Lophiosilurus alexandri foram coletadas para determinar os perfis de aminoácidos e ácidos graxos. A proteína bruta não alterou durante o desenvolvimento inicial e a concentração de lipídios foi maior na NHL. O conteúdo dos aminoácidos indispensáveis (IAA) isoleucina, leucina e valina diminuíram em LPL, enquanto nos ovos e NHL eles permaneceram com valores elevados e semelhantes entre si. Os aminoácidos dispensáveis (DAA), como ácido aspártico, tirosina e glicina, aumentaram em LPL, enquanto a alanina diminuiu. A porcentagem de lipídios neutros aumentou em LPL. O teor de ácidos graxos saturados diminuiu durante a ontogenia, enquanto os ácidos graxos monoinsaturados diminuíram apenas em LPL. O teor de ácidos graxos poliinsaturados foi maior em LPL. Os ácidos graxos polares foram encontrados em porcentagens mais altas em ovos e NHL, e menores em LPL. O teor de ácidos graxos saturados reduziu durante o desenvolvimento ontogenético, enquanto que os ácidos graxos monoinsaturados diminuíram apenas em LPL. O teor de ácidos graxos poliinsaturados foi maior em LPL. O conteúdo de proteínas foi mantido durante o desenvolvimento ontogenético, enquanto as classes de aminoácidos sofreram mudanças. Lophiosilurus alexandri usa preferencialmente ácidos graxos saturados e monossaturados como fonte de energia durante o desenvolvimento inicial.(AU)

Description of the composition of fatty acids and lipids in the breeders muscle, oocytes and in the embryonic development of Brycon orthotaenia (Günther, 1864).

The objective of this work was to evaluate the fatty acid and lipid composition of oocytes, newly hatched larvae (NHL), first feeding larvae (FFL) and muscle tissue of female Brycon orthotaenia broodstock. Total and polar lipid was significantly (P<0.05) abundant in oocytes and larvae in different stages of development. The lowest content (P<0.05) of total lipids was found in the muscles, whereas total lipid content of oocytes, NHL and FFL did not show any significant difference. Polar lipid content was different (P<0.05) between NHL and FFL. For the neutral the lowest values of C18:2n 6 occurred during the initial feeding period, whilst C20:4n 6 (AA) exhibited the highest percentage in FFL (P<0.05). C22:6n 3 (DHA) was highest (P<0.05) in FFL. The neutral lipid n-9 and n-6 was highest in muscle of females. The n-3HUFA was highest in NHL and in FFL, n-6HUFA was highest in FFL (P<0.05). The ratios of DHA/EPA were higher (P<0.05) in oocytes and FFL. In fatty acids of polar lipids, C20:5n 3 (EPA) did not show differences (P>0.05) between stages. C18:3n 3 was highest (P<0.05) in NHL and FFL. C20:4n 6 (AA) and C22:6n 3 (DHA) showed the highest percentages during the larval stages. The fatty acids n-3 series was significantly higher (P<0.05) in FFL. The n-6HUFA was highest during development larval (P<0.05). The increases DHA reflects the ability of the species to elongate and desaturate to obtain n-3HUFA from 18:3n 3, shows the importance of this fatty acid during early development.