Free Amino Acids in Pacu, Piaractus mesopotamicus, Eggs and Larvae

Abstract

Free amino acids (FAA) are used principally as substrate in protein synthesis and the source of energy in aerobic catabolism. In marine fish, embryo and larvae FAA are used to maintain body fluid osmolality during fish early development. However, there is essentially no information about FAA concentrations in early ontogeny of freshwater neotropical species in comparison to marine fishes. Therefore, the aim of this study was to evaluate the FAA concentrations in pacu, Piaractus mesopotamicus, eggs and larvae. Broodstock fish were induced to spawn and ovulated females were stripped of their eggs and immediately sampled for analysis. Larvae were sampled right after hatching (HL) and after the completion of the yolk-sac absorption (YSA). The wet weight of the HL and YSA larvae amounted to 0.5 ± 0.1 mg and 1.1 ± 0.3 mg, respectively. HL larvae showed higher levels of most of the indispensable amino acids (IAA) in comparison to eggs and YSA larvae. Exceptions were observed with His and Trp that showed higher or similar levels, respectively, in YSA larvae. The FAA Orn, Tau, Glu, Gln, Gly, and Tyr increased concentrations in both larval stages while that of Tau was found in higher concentration in all analyzed stages. Also, the concentrations of Asn, Ala, Pro, Ser, and Asp were higher in HL larvae. Both larval stages displayed a rise in total free IAA/total free DAA (dispensable amino acids) ratio. The authors conclude that the highest level of FAA in HL pacu larvae is indicative of active proteolysis of yolk reserves and a probable catabolism regulation of some FAA through spare-effect. In addition, Tau is one of the major FAA occurring during pacu ontogeny and may be performing regulation on body fluid osmolality regulation.

Ontogenetic changes in digestive enzyme activities and the amino acid profile of starry flounder Platichthys stellatus

“…Several marine fi sh larvae favor using NAAs rather than EAAs as energy substrates, indicating that they have the ability to control AA metabolism (Conceição et al, 2001(Conceição et al, , 2003Rønnestad et al, 2001;Portella et al, 2013). However, the continuous decrease in the FEAA/FNAA ratio in our study indicates that more FEAAs were depleted than FNAAs.…”

“…The protein amino acid (PAA) profi le also follows species-specifi c changes during larval development (Aragão et al, 2000). Pacu ( Piaractus mesopotamicu ) larvae utilize certain AAs and retain others for later developmental stages, which leads to a diff erence in the larval AA profi le (Portella et al, 2013). Thus, changes in the AA profi les of fi sh larvae have important implications in terms of AA requirements (Conceição et al, 1997;Aragão et al, 2004).…”

Relaciones alométricas en estadios tempranos de la especie Brycon moorei Steindachner (Characidae), en condiciones controladas

“…Con respecto al crecimiento en el periodo experimental para B. moorei reflejado en la relación de la LT y LE versus HPE, se observa entre las 150 y las 250 HPE una queda en el crecimiento, comparado con las etapas anteriores y la posterior a las 250 HPE, este patrón en el crecimiento puede estar influenciado por el cambio en el protocolo de alimentación, el cual coincide con el inicio de la dieta; se conoce que el crecimiento y la composición química corporal de los peces pueden ser influenciados por la manipulación de los nutrientes de las dietas (Dabrowski, 1984), además en larvas de desarrollo indirecto la transición a dieta seca, después del alimento vivo, puede presentar este tipo de comportamientos, por lo que se recomienda el diseño de protocolos de alimentación (Portella, Leitão, Takata, y Lopes, 2012), asociado al seguimiento de la calidad del agua, el tipo de contendor y aspectos etológicos de la especie (David-Ruales, y Castañeda-Álvarez, 2010)…”

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

“…Trp is the main precursor of serotonin and is known to affect food intake and aggression in fish (Li et al, 2007). Portella et al (2013) stated that in Piaractus mesopotamicus, Trp was probably maintained for the synthesis of serotonin and melatonin. A similar behavior was reported throughout development of Latris lineata (Brown et al, 2005).…”