Isótopos estables ( ?15 N ) como herramienta para medir la calidad de alimentos comerciales para lobina rayada ( Morone saxatilis ) en jaulas marinas

Aquafeed quality for striped bass (Morone saxatilis) was evaluated under commercial conditions in sea cages using stable isotopes as tracers for nitrogen. Using a crossover experimental design, fish that were fed during 270 days with aquafeed A was switched to aquafeed B during the following 160 days. Samples of aquafeeds and of muscle, and liver tissues were analyzed before and during feeding with aquafeed B. The isotopic value from diet A and muscle and liver tissues after being fed during 270 days were 10.3, 14.6 and 13.1 resulting in a discrimination factor of 4.3 and 2.7 for muscle and liver. At day 90 and 160 the discrimination factor reach the equilibrium both for muscle and liver tissues (2.3 and 0.0). It was concluded that diet B hadbetter quality as a result of a lower discrimination factor than that observed with diet A. The nitrogen stable isotope is a reliable tool to evaluate aquafeeds quality under commercial conditions where the other estimations like feed intake and apparent digestibility are difficult to obtain.La calidad entre dos alimentos comerciales (A y B) se evaluó utilizando isótopos estables como trazadores de la retención de nitrógeno (?15N) en lobina rayada (Morone saxatilis) mantenidas en jaulas marinas. Con base en un diseño cruzado, se utilizaron peces que habían sido alimentados durante 270 días con el alimento A, mismos que fueron cambiados al alimento B durante otros 160 días. Se analizaronmuestras de los alimentos comerciales y de tejido de músculo e hígado antes y durante la alimentación con el alimento comercial B, para determinar su composición química e isotópica. El valor isotópico de losalimentos comerciales, músculo e hígado, al término de la alimentación con el alimento A fue de 10.3, 14.6 y 13.1, lo que refleja un factor de discriminación para músculo e hígado de 4.3 y 2.7, respectivamente. Al hacer el cambio al alimento B (11.09), se observó una reducción en los valores isotópicos. Para los días 90 y 160, los valores de discriminación ya eran casi constantes tanto para músculo como para hígado (2.3 y 0.0). Se concluye que el alimento B presentó una mejor calidad al incorporarse con un menor factor de discriminación que lo observado con el alimento A. La técnica de isótopos estables demostró ser una herramienta útil para monitorear la calidad del alimento bajo condiciones comerciales, ya que mide directamente la eficiencia de la retención del nitrógeno, mientras que en otras pruebas como las de consumo y de digestibilidad aparente, es difícil de obtener

Total or partial replacement of fishmeal with soybean meal in the diet of the Pacific fat sleeper Dormitator latifrons juveniles

Groups of Dormitator latifrons in triplicate (4.1 ± 2.0 g and 6.2 ± 1.0 cm) were fed experimental diets containing four levels of substitution of fishmeal (FM) by soybean meal (SM) (0, 40, 70, and 100%, respectively). The diets were formulated to be isoproteic (35% crude protein) and isolipidic (8.0% crude lipids). The effect of each treatment on growth was evaluated and its implications on the cost of feeding. After 60 days of feeding, there were no significant differences in the fish's proximate composition (P < 0.05). There were no significant differences between the diets (P < 0.05) in the evaluated biological indices: total growth increase (TGI), specific growth rate (SGR), thermal growth coefficient (TGC), and survival (%). Feeding costs decreased significantly as the proportion of soybean meal in the diet increased. The results indicated that substituting FM by up to 100% of SM can promote adequate growth in D. latifrons without affecting body composition and survival while also reducing operative costs during the fattening process.Fil: Badillo Zapata, Daniel. Universidad de Guadalajara; MéxicoFil: Musin, Gabriela Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Palma Cancino, David J.. Universidad de Guadalajara; MéxicoFil: Guerrero Galván, Saúl R.. Universidad de Guadalajara; MéxicoFil: Chong Carrillo, Olimpia. Universidad de Guadalajara; MéxicoFil: Vega Villasante, Fernando. Universidad de Guadalajara; Méxic

Survival of the prawn Macrobrachium tenellum (Smith, 1871) in confinement with the native fish Dormitator latifrons (Richardson, 1844)

Objective: The aim of this study was to test the survival of Macrobrachium tenellum in different confinement conditions with Dormitator latifrons. Design/methodology/approach: Using wild specimens acclimated to captive conditions of both species, three trials of different proportion were performed with treatments consisting in the presence/absence of food and shelters. Prawn/fish proportion for the assays were: 15/15 for T1, 15/3 for T2 and 10/3 for T3. In assays T1 and T2 juvenile prawns and fish were used, while in T3 post-larvae prawns and pre-juvenile fish were used. To test the survival with or without fed, it was schedule a four-day feeding ad libitum period, following by a two-day fed depravation period in all the assays. Results: In assays with juveniles of M. tenellum the survival rate was superior to 80% with or without shelter, when T1 showed 97-100% survival; meanwhile T3 presented a 56.67 % of survival, suggesting it’s necessary to use only juvenile prawns in co-culture systems. The use of shelters and fed deprivation had no significant effects on the survival of prawns. Limitations on study/implications: M. tenellum is an important aquatic resource for the central Mexican Pacific, region in which the D. latifrons is a representative native fish with a developing aquaculture. A polyculture or co-culture system with these species can accelerate the sustainability of both species productions. Findings/conclusions: The results suggest this polyculture system may be feasible, and longer duration culture are recommended.Objective: The aim of this study was to test the survival of Macrobrachium tenellum in different confinement conditions with Dormitator latifrons. Design/methodology/approach: Using wild specimens acclimated to captive conditions of both species, three trials of different proportion were performed with treatments consisting in the presence/absence of food and shelters. Prawn/fish proportion for the assays were: 15/15 for T1, 15/3 for T2 and 10/3 for T3. In assays T1 and T2 juvenile prawns and fish were used, while in T3 post-larvae prawns and pre-juvenile fish were used. To test the survival with or without fed, it was schedule a four-day feeding ad libitum period, following by a two-day fed depravation period in all the assays. Results: In assays with juveniles of M. tenellum the survival rate was superior to 80% with or without shelter, when T1 showed 97-100% survival; meanwhile T3 presented a 56.67 % of survival, suggesting it’s necessary to use only juvenile prawns in co-culture systems. The use of shelters and fed deprivation had no significant effects on the survival of prawns. Limitations on study/implications: M. tenellum is an important aquatic resource for the central Mexican Pacific, region in which the D. latifrons is a representative native fish with a developing aquaculture. A polyculture or co-culture system with these species can accelerate the sustainability of both species productions. Findings/conclusions: The results suggest this polyculture system may be feasible, and longer duration culture are recommended

Levels of fat for potential consumption of juvenile Ambystoma mexi-canum (Shaw & Nodder, 1798) axolotls: Lipid levels

Objective: The present study focused on the effect of different lipid levels on growth (weight and length) and survival in juvenile Ambystoma mexicanum. Design/methodology/approach: Four diets with the same 45% protein level and different lipid levels: 6, 8, 10 and 12% were tested for a period of 81 days. For the preparation of the diets, two key ingredients were used, such as fishmeal and fish oil, these as protein base and lipid source. The experiment consisted of placing six organisms per experimental unit in tubs with 40 L of water for a period of 81 days; period during which four biometrics were performed, the organisms were fed every 48 hours to the weight of their biomass. The digestibility of the diets, initial and final height, initial and final weight, weight gained, weight gained per day, specific growth rate, survival, Fulton index and protein efficiency rate were recorded. Results: At the end of the experiment, significant differences (p &gt; 0.05) were observed in the growth and survival of the axolotls in the diets of 8, 10 and 12% lipids. Limitations on study/implications: A wider range of lipid levels could not be tested, due to the number of individuals available for the experiment. Findings/conclusions: According to the data obtained in this study, it is recommended to include a level of 45% protein and 8% lipids in the diets of juvenile Ambystoma mexicanum, for their better development and nutrition.Objective: The present study focused on the effect of different lipid levels on growth (weight and length) and survival in juvenile Ambystoma mexicanum. Design/methodology/approach: Four diets with the same 45% protein level and different lipid levels: 6, 8, 10 and 12% were tested for a period of 81 days. For the preparation of the diets, two key ingredients were used, such as fishmeal and fish oil, these as protein base and lipid source. The experiment consisted of placing six organisms per experimental unit in tubs with 40 L of water for a period of 81 days; period during which four biometrics were performed, the organisms were fed every 48 hours to the weight of their biomass. The digestibility of the diets, initial and final height, initial and final weight, weight gained, weight gained per day, specific growth rate, survival, Fulton index and protein efficiency rate were recorded. Results: At the end of the experiment, significant differences (p &gt; 0.05) were observed in the growth and survival of the axolotls in the diets of 8, 10 and 12% lipids. Limitations on study/implications: A wider range of lipid levels could not be tested, due to the number of individuals available for the experiment. Findings/conclusions: According to the data obtained in this study, it is recommended to include a level of 45% protein and 8% lipids in the diets of juvenile Ambystoma mexicanum, for their better development and nutritio

Acute toxicity induced by treated sewage to zebrafish (Danio rerio)

Objective: Acute toxicity markers in zebrafish caused by exposure to treated sewage from two sewage treatment plants were evaluated in order to obtain accurate and relevant information on the potential environmental health risks associated with these waters. Design/methodology/approach: The acute toxicity assessment was performed according to the guidelines proposed by the Organization for Economic Cooperation and Development (OECD). Five proportions of each type of water treated with dechlorinated tap water (20, 40, 60, 60, 80 and 100%) were tested to determine the Median Lethal Dilution (LDil50). The dechlorinated tap water was the negative control and as a positive control potassium dichromate at Mean Lethal Concentration (0.065 mg/L). The description of the teratogenic effects was carried out using the spine biomarker, which consists of dividing the fish into three sections to identify the damaged area. Results: The results revealed that the mixture of treated sewage (mCl) and treated sewage disinfected with sodium hypochlorite (NaClO) caused toxic effects in zebrafish embryos. On the other hand, treated sewage from the Macroplanta de Bahía de Banderas (BBdClO) was not toxic at 96 hours of exposure. Limitations on study/implications: It would be advisable to characterize the treated sewage from these two sewage treatment plants. Findings/conclusions: These findings underscore the importance of assessing the toxicity of treated sewage and its short- and long-term effects on aquatic organisms, providing valuable information for water resource management and environmental protection.Objetivo: Se evaluaron marcadores de toxicidad aguda en pez cebra causados por la exposición a aguas residuales tratadas de dos plantas de tratamiento de aguas residuales para obtener información precisa y relevante sobre los riesgos potenciales para la salud ambiental asociados con estas aguas. Diseño/metodología/aproximación: La evaluación de la toxicidad aguda se realizó de acuerdo a los lineamientos propuestos por la Organización para la Cooperación y el Desarrollo Económicos (OECD). Para determinar la Dilución Letal Media (LDil50) se analizaron cinco proporciones de cada tipo de agua tratada con agua del grifo declorada (20, 40, 60, 80 y 100%). La descripción de los efectos teratogénicos se realizó mediante el biomarcador de columna vertebral. Resultados: Los resultados revelaron que la mezcla de agua residual tratada (mCl) y el agua residual tratada desinfectada con hipoclorito de sodio (NaClO) causaron efectos tóxicos en los embriones del pez cebra, como letalidad, malformaciones y alteraciones cardiacas. Por otra parte, el agua residual tratada de la Macroplanta de Bahía de Banderas (BBdClO) no fue tóxica a 96 horas de exposición. Limitaciones del estudio/implicaciones: Sería recomendable caracterizar las aguas residuales tratadas de estas dos plantas de tratamiento. Hallazgos/conclusiones: Estos hallazgos subrayan la importancia de evaluar la toxicidad de las aguas residuales tratadas y sus efectos a corto y largo plazo en los organismos acuáticos, proporcionando información valiosa para la gestión de recursos hídricos y la protección del medio ambiente

Biology and use of the Pacific fat sleeper Dormitator latifrons (Richardson, 1844): state of the art review

The present work is a review of the literature on the native Mexican fish Dormitator latifrons. The aim is to contribute to the integration and systematization of current knowledge to make it easier to identify existing knowledge gaps and breakthroghs Moreover, promote the successful cultivation and protection of this species whose consumption is increasing in Latin America. A review of the articles related to D. latifrons published in international and regional databases was carried out. The articles reviewed focus on taxonomy and systematics, phylogenetic, geographic distribution, ecology, physiology, reproduction, development, pathology, health, and the technologies used to cultivate this fish species. The conclusion is that, even though the cultivation of D. latifrons is of commercial interest in some countries, there are still significant gaps in our knowledge of biology and, consequently, the domestication potential of the species. Filling these gaps will require systematic research efforts on protecting natural populations and improving mass cultivation techniques.Fil: Vega Villasante, Fernando. Universidad de Guadalajara; MéxicoFil: Ruiz González, Luis E.. Universidad de Guadalajara; MéxicoFil: Chong Carrillo, Olimpia. Universidad de Guadalajara; MéxicoFil: Basto Rosales, Mao E. R.. Tecnológico Nacional de Bahía de Banderas; MéxicoFil: Palma Cancino, David J.. Universidad de Guadalajara; MéxicoFil: Tintos Gómez, Adrián. Universidad Tecnológica de Manzanillo; MéxicoFil: Montoya Martínez, Cynthia E.. Universidad de Guadalajara; MéxicoFil: Kelly Gutiérrez, Liza D.. Universidad de Guadalajara; MéxicoFil: Guerrero Galván, Saúl R.. Universidad de Guadalajara; MéxicoFil: Ponce Palafox, Jesús T.. Universidad Autónoma de Nayarit; MéxicoFil: Zapata, Ana. Universidad de Guadalajara; MéxicoFil: Musin, Gabriela Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Badillo Zapata, Daniel. Universidad de Guadalajara; Méxic

Palatability of animal oils included in the diet of the Mexican axolotl and its effect on growth and survival

Objective: The growth, survival and condition factor of Ambystoma mexicanum juveniles fed with three commercial feed-based diets coated with different animal oils as potential palatability enhancers were evaluated. Methodology: Three diets were prepared using commercial feed coated with fish, chicken and krill oil. The experiment lasted 81 days, the food was provided to the axolotls (6 per experimental unit, in triplicate) every 48 h, at 4% of the total biomass. The total weight of each experimental unit was recorded every 15 days, at the end of the experiment individual weight and height and survival were recorded. The following variables were calculated: Fulton's K, specific growth rate, coefficient of variation of final weight and size heterogeneity. Results: All three treatments showed an increase in total biomass, with a trend towards better performance in chicken and fish oil treatments compared to krill oil. When performing the statistical analysis, it was found that there were no significant differences among the treatments for any of the variables recorded. Implications: The three oils used in the present study were good palatable agents in the food intake of A. mexicanum. Conclusions: It is recommended to use chicken oil as an attractant additive in the formulation of a specific diet due to its low cost.Objective: The growth, survival, and condition factor of Ambystoma mexicanum juveniles fed with three commercial feed-based diets coated with different animal oils as potential palatability enhancers were evaluated. Methodology: Three diets were prepared using commercial feed coated with fish, chicken, and krill oil. The experiment lasted 81 days, the food was provided to the axolotls (6 per experimental unit, in triplicate) every 48 h, at 4% of the total biomass. The total weight of each experimental unit was recorded every 15 days, at the end of the experiment individual weight and height and survival were recorded. The following variables were calculated: Fulton's K, specific growth rate, coefficient of variation of final weight and size heterogeneity. Results: All three treatments showed an increase in total biomass, with a trend towards better performance in chicken and fish oil treatments compared to krill oil. When performing the statistical analysis, it was found that there were no significant differences among the treatments for any of the variables recorded. Implications: The three oils used in the present study were good palatable agents in the food intake of A. mexicanum. Conclusions: It is recommended to use chicken oil as an attractant additive in the formulation of a specific diet due to its low cost

El uso de hongos macroscópicos como inmunoestimulantes en peces teleósteos: estado del arte al 2018

Background. Different methods are currently used for the prevention and control of diseases in aquaculture. Prophylaxis with immunostimulants from microscopic fungi provides protection against diseases and increases resistance to parasites. In this context, Basidiomycota fungi could have high potential for use in aquaculture because they contain different compounds, such as fungal proteins, polysaccharides, terpenoids, vitamins, and minerals, which could work as immunostimulants. Goals. Collect and disseminate the information on species of macroscopic fungi that have been used as immunostimulants in the farming of teleost fish and the fungi that have not been tested in fish but have shown positive results in other organisms. Methods. We gather, discuss and compare the experimental, scientific and theoretical literature related to the immunostimulant effect of macroscopic fungi in the cultivation of teleosts, as well as fungi whose stimulating effect&nbsp;has been positive in other organisms. Results. We evaluated more than 50 species of fungi with immunostimulating properties. Nevertheless, in recent years, the effects of only eight species of macromycetes, belonging to the genera Ganoderma, Inonotus, Lentinula, Pleurotus, and Trametes, have been evaluated in 17 published papers regarding the immune response of nine species of fish. Seven of these papers are about isolated glucans, six about crude and alcoholic extracts, two about pulverized basidiomata, and one about a mushroom fermented by-product. Conclusions. Due to the limited information on the immunostimulating effect of macromycetes on fish, more research is needed regarding other fungi species with immunostimulant properties, the correct determination of fungi species, their culture, and in vivo and in vitro tests that confirm their immune system effects on the model organism and target organism. &nbsp;Antecedentes. Actualmente se utilizan diferentes métodos para la prevención y control de enfermedades en la acuicultura. La profilaxis con inmunoestimulantes a partir de hongos macroscópicos proporciona protección ante enfermedades y aumenta la resistencia a parásitos. En este contexto, los hongos Basidiomycota podrían tener un alto potencial para su uso acuícola, ya que contienen diferentes compuestos, como proteínas fúngicas, polisacáridos, terpenoides, vitaminas y minerales, que podrían tener un efecto inmunoestimulante. Objetivos. Analizar la información existente relativa a las especies de hongos macroscópicos que han sido evaluadas como inmunoestimulantes en el cultivo de peces teleósteos y también la de aquéllos que no han sido probados en peces pero que han mostrado resultados positivos en la respuesta inmune en otros organismos. Métodos. Se reunió, expuso y comparó la literatura experimental, científica y teórica relacionada con el efecto inmunoestimulante de los hongos macroscópicos en el cultivo de teleósteos así como la relativa a hongos cuyo efecto estimulante ha sido positivo en otros organismos. Resultados. Actualmente se han comprobado las propiedades inmunoestimulantes de más de 50 especies de hongos macroscópicos. No obstante, en 17 investigaciones publicadas durante los últimos años sólo se ha evaluado el efecto sobre la respuesta inmune de nueve especies de peces ante ocho especies de hongos: Ganoderma, Inonotus, Lentinula, Pleurotus, Phellinus y Trametes. De dichas publicaciones, siete consisten en la evaluación de glucanos purificados, seis de extractos crudos o alcohólicos, dos de basidiomas pulverizados y uno de un subproducto de hongo fermentado. Conclusiones. Debido a la escasa información existente sobre el efecto inmunoestimulante de macromicetes en peces, es preciso llevar a cabo más investigaciones que aborden su potencial en otras especies, que se estudie su cultivo y su correcta determinación, y se realicen pruebas in vitro e in vivo, tanto del organismo modelo como de organismos blanco, para confirmar sus efectos sobre el sistema inmune

Somatic indices and nutritional composition of the roe of the native fish Dormitator latifrons: no aplica

Objective: To evaluate some reproductive aspects of D. latifrons and the nutritional quality of its eggs. Design/methods/approach: Eighty-two fish were randomly collected (August 2021), and their sex, length, weight, somatic indices, Fulton condition index (K), proximate composition, and amino acid and lipid composition (fatty acids) of the gonads were determined. Results: Of the total specimens collected, 62% were females; length and weight values were higher in males, but their gonadosomatic index (GSI) was lower than in females. Somatic indices did not show differences between different weight ranges. In the roe of D. latifrons, the average proximate composition was 24.3% protein and 8.5% lipids. The most abundant essential amino acids were leucine and lysine. Linoleic acid (C18:2n6) was the fatty acid with the highest concentration. Limitations/implications: It is necessary to complement the analysis of the amino acid and fatty acid profile of the roe in wild organisms to relate the changes caused by balanced feed. Findings/conclusions: This study shows that the D. latifrons roe is a good source of amino acids and PUFA. Keywords: proximate composition, fatty acids, essential amino acidsObjective: To evaluate some reproductive aspects of D. latifrons and the nutritional quality of its eggs. Design/methods/approach: Eighty-two fish were randomly collected (August 2021), and their sex, length, weight, somatic indices, Fulton condition index (K), proximate composition, and amino acid and lipid composition (fatty acids) of the gonads were determined. Results: Of the total specimens collected, 62% were females; length and weight values were higher in males, but their gonadosomatic index (GSI) was lower than in females. Somatic indices did not show differences between different weight ranges. In the roe of D. latifrons, the average proximate composition was 24.3% protein and 8.5% lipids. The most abundant essential amino acids were leucine and lysine. Linoleic acid (C18:2n6) was the fatty acid with the highest concentration. Limitations/implications: It is necessary to complement the analysis of the amino acid and fatty acid profile of the roe in wild organisms to relate the changes caused by balanced feed. Findings/conclusions: This study shows that the D. latifrons roe is a good source of amino acids and PUFA

Yield, sensory and proximate analysis of Dormitator latifrons fillets prepared with different cooking methods

Objective: To evaluate the effect of four cooking methods (steaming, griddling, baking or pan-frying) on the carcass and fillet yield and on the degree of sensory acceptance and proximate composition of fillets from Dormitator latifrons. Design/methods/approach: Whole and gutted fish, and the fillets cut from them, were weighed to determine yield. The fillets were cooked by steaming, griddling, baking or pan-frying according local traditional methods. The organoleptic characteristics (color, odor, general appearance, taste, texture, and juiciness) were evaluated using a 5-point hedonic scale. The proximate analysis was done on raw and cooked fish samples. Results: The average weight of the fish was 446.0 ± 63.4 g, with a carcass yield of 83.0% and a fillet yield of 18.7%. The organoleptic characteristics did not show significant differences, with all treatments obtaining average scores above 4 (like) in the hedonic scale. Regarding the proximate composition, the protein and ash content of the fish fillets increased with most of the cooking methods. The highest lipid content was obtained with the frying method. Limitations/implications: The evaluation of nutritional quality was done at the proximate level only¸ since it was considered that the protein nutritional quality (fillet protein), would not be modified substantially. Findings/conclusions: All four cooking methods were associated with a high level of acceptance and good nutritional quality, although the increase in lipid content of fried fish could have a detrimental effect on consumer health, in the case of a high level of consumption. Keywords: Pacific fat sleeper; nutritional quality; heat treatment.Objective: To evaluate the effect of four cooking methods (steaming, griddling, baking, or pan-frying) on the carcass and fillet yield and on the degree of sensory acceptance and proximate composition of fillets from Dormitator latifrons. Design/methods/approach: Whole and gutted fish, and the fillets cut from them, were weighed to determine yield. The fillets were cooked by steaming, griddling, baking, or pan-frying according to local traditional methods. The organoleptic characteristics (color, odor, general appearance, taste, texture, and juiciness) were evaluated using a 5-point hedonic scale. The proximate analysis was done on raw and cooked fish samples. Results: The average weight of the fish was 446.0 ±63.4 g, with a carcass yield of 83.0% and a fillet yield of 18.7%. The organoleptic characteristics did not show significant differences, with all treatments obtaining average scores above 4 (like) in the hedonic scale. Regarding the proximate composition, the protein and ash content of the fish fillets increased with most of the cooking methods. The highest lipid content was obtained with the frying method. Limitations/implications: The evaluation of nutritional quality was done at the proximate level only¸ since it was considered that the protein nutritional quality (fillet protein), would not be modified substantially. Findings/conclusions: All four cooking methods were associated with a high level of acceptance and good nutritional quality, although the increase in lipid content of fried fish could have a detrimental effect on consumer health, in the case of a high level of consumption