Resumen.-Pequeños Brachionus sp. (130-230 µm) en 2011-2012 y superpequeños Brachionus sp. (110-140 µm) en 2013-2014, se cultivaron en un sistema por lotes (ciclos de 3 o 4 días) y en sistemas semi-continuos. Para la alimentación de rotíferos se usaron microalga concentrada (Nannochloropsis sp.), dosificada continuamente con una bomba peristáltica. Las condiciones del cultivo fueron provistas con aire, oxígeno e hidroximetanosulfonato de sodio. La producción total promedio por día fue 552, 602 y 459 millones de rotíferos d -1, con una densidad final promedio de cosecha de 1.099 rotíferos mL -1 , 1.052 rotíferos mL -1 y 1.015 rotíferos mL -1 , para tres días (3-d), cuatro días (4-d) del sistema de producción por lotes y el sistema de producción semi-continuo, respectivamente. Los valores promedios producidos de rotíferos fueron adecuados para suplir los requerimientos de rotíferos en los ciclos de cultivos piloto, para producir 169 x 10 3 /año (2012) a 564 x 10 3 (2013) juveniles/año con una demanda media anual de 83,9 x 10 6 rotíferos/1000 juveniles producidos. Los costos totales operacionales por millón de rotíferos/día fueron bajos con el sistema de cultivo semi-continuo ($0,23), seguido por el sistema por lotes de 4-d ($0,55) y el sistema por lotes de 3-d ($0,59). Estos costos de producción fueron más bajos que otros reportes de producción con alimento artificial y sistemas de recirculación. Los principales componentes de los costos operacionales fueron alimento (71-77%) y personal (7-11%). La mejor estabilidad y confiabilidad de la producción fue con el sistema semi-continuo, el cual garantizó las cantidades requeridas diariamente para los cultivos de cría larval más altos. Para posibles mejoras y aumento de la producción, la discusión se basa en términos de eficiencia financiera.Palabras clave: Sistema de cultivo por lotes, sistema de cultivo semi-continuo, análisis de costos operacionales, larva de peces marinos , 1,052 rotifers mL -1 and 1,015 rotifers mL -1 were harvested in three day (3-d) and four day (4-d) batch culture systems and semi-continuous culture systems, respectively. The average values of rotifers produced were adequate to supply the rotifers required in the parallel pilot rearing larval cycles, and 169 x 10 3 /yr (2012) to 564 x 10 3 (2013) juveniles/yr were produced with a mean annual demand of 83.9 x 10 6 rotifers/1,000 juveniles produced. The total operational cost per million rotifers/day was lower for the semi-continuous culture system ($0.23), followed by the 4-d batch system ($0.55) and 3-d batch system ($0.59). These production costs were lower than those of other reports with artificial feeds and recirculation systems. The main components of the total operational cost was food (71-77%) and labor (7-11%). The best production stability and reliability were in the semicontinuous system, which best met the required daily quantities for the larval rearing trials. For possible improvements and increased production, the results are discussed in terms of financial efficiency.
Abstract.-Benzocaine, 2-phenoxyethanol and MS-222 were tested as anaesthetics for several handling procedures with spotted rose snapper Lutjanus guttatus broodstock. Significant differences in time for induction and recovery were found with specific doses, as well as a direct correlation between the dose and the induction time. Each procedure demanded specific anaesthesia levels where the stage of deep anaesthesia should not be surpassed. The most effective agent for inducing deep anaesthesia was MS-222, with the least amount of time required for induction and recovery when using 100 mg l -1 . It was followed by 250 μl l -1 of 2-phenoxyethanol, which was less costly.
The embryonic development of the bullseye puffer, Sphoeroides annulatus, was characterized on the basis of the theory of saltatory ontogeny. This theory predicts a correlative relationship between the ontogeny‐type in an altricial‐precocial spectrum and the habitat that a species occupies within an unstable‐stable environmental spectrum. Because S. annulatus inhabits a variety of unstable environments along a wide latitudinal range, the hypothesis that this species presents one of the most altricial embryonic developments among tetraodontids was tested. Based on major developmental events that marked the ontogenetic thresholds nine embryonic steps were identified. Developmental features such as small adhesives eggs, lack of vitelline circulation, small free embryos swimming up at hatching guided by positive phototaxis, and small first‐feeding larvae actively swam in the water column, suggest that S. annulatus belongs to the reproductive guild of the nonguarders‐lithopelagophils. Moreover, a comparative analysis of the developmental sequences, egg size, and first‐feeding larvae size between tetraodontids confirms the hypothesis of this study and supports the evolutionary principle of the altricial‐precocial spectrum postulated in the theory of saltatory ontogeny.
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