ABSTRACT In order to provide information on the current knowledge about the native fish Dormitator latifrons and identify the gaps that must be filled to achieve correct resource management, a scientometric study was carried out using different scientific databases. A total of 103 publications were registered between the years 1972 and 2021. Results indicate that the species has been addressed since 2001 with less than one publication per year, with 2008 being the year with the highest number of publications (10). The main topics addressed were ecology, physiology, and parasitology of fish. The available knowledge generated about the species is concentrated in 68 journals, with Mexico as the most productive country, followed by USA and Ecuador, and the most productive research centers about this fish were Mexico’s Instituto Politécnico Nacional and Universidad de Guadalajara. A total of 285 authors were detected contributing knowledge to the species, with Violante-González in the top with ten publications. The co-authorship co-occurrence maps suggest there is no solid collaborative relationship between the scientific community and that the information generated is insufficient for conserving and exploiting this fish. It is essential to increase the study of thematic areas that allow their comprehensive management in the medium term; topics like reproduction in captivity, aquaculture, and nutrition must be addressed in the future to assure a sustainable use of this resource.

ABSTRACT Background: The legume Cannavalia ensiformis is an excellent source of energy, protein, vitamins and minerals to be used in animal production; however, it contains antinutritional factors (ANF), which limit its use for fishes. Goals: In this study 7 flours obtained from the processes of hydration, acid extraction, decorticating, cooking, germination, autoclaving and degreasing of the seeds of C. ensiformis were evaluated as means of elimination of ANF. Methods: The nutritional values of the meals were corroborated with proximal chemical analysis and in vitro digestibility, determining the degree of hydrolysis (GH%) of the flours of C. ensiformis obtained by pH STAT, the release of total amino acids (TAAL, μg mL-1) was calculated, using multienzymatic extracts of stomach and intestine of O.niloticus juveniles. Results: The acidic/alkaline GH values for cooked C. ensiformis flour were 0.76 ± 0.01% / 6.04 ± 0.37%, being significantly higher with respect to the other flours. The values of acidic/alkaline TAAL (µg mL-1) of this cooked flour (0.02 ± 0.006 / 0.40 ± 0.02) were significantly higher in the alkaline phase in relation to the other treatments. Conclusion: We detected that cooked meal of C. ensiformis, allow to be used as a source of protein in diets for Oreochromis niloticus.

RESUMEN Antecedentes: La leguminosa Cannavalia ensiformis es una excelente fuente de energía, proteína, vitaminas y minerales para ser utilizada en la alimentación animal; sin embargo, contiene factores antinutricionales (FAN), que limitan su utilización en la alimentación de peces. Objetivo: En este estudio se evaluaron 7 harinas obtenidas de los procesos de hidratación, extracción ácida, decorticado, cocción, germinado, autoclave y desgrasado de las semillas de C. ensiformis como medios de eliminación de FAN. Métodos: La calidad nutricional de las harinas fueron corroborados con análisis químicos proximales y digestibilidad in vitro, determinando el grado de hidrólisis (GH, %) de las harinas de C. ensiformis obtenidas mediante pH STAT, se calculó la liberación de aminoácidos totales (AALT, µg mL-1), utilizando extractos multienzimáticos de estómago e intestino de juveniles de O. niloticus. Resultados: Los valores de GH ácido/alcalino para la harina de C. ensiformis cocida fue de 0.76 ± 0.01%/ 6.04 ± 0.37%, siendo significativamente mayor con respecto a las otras harinas. Los valores de AALT ácido/alcalino (µg mL-1) de esta harina cocida (0.02 ± 0.006/ 0.40 ± 0.02) fueron significativamente mayores en la fase alcalina en relación a las otros tratamientos. Conclusión: Se detectó que la harina cocida deC. ensiformis, permite ser utilizada como fuente de proteína en dietas para Oreochromis niloticus.

ABSTRACT This study assessed the effect of protein level in diet and feeding schedule on the digestive enzymatic activity of Macrobrachium tenellum juveniles. Freshwater prawn juveniles (0.31 ± 0.004 g and 32.48 ± 0.27 mm) were fed diets with 20, 25, 30, 35 and 40% crude protein (CP) (p/p). In a second experiment, feeding schedules were assessed at 08:00, 14:00 and 20:00 h with feed at 30% CP with juveniles of 0.22 ± 0.002 g and 29.36 ± 0.28 mm. In both experiments, five organisms were sampled after 60 days of treatment in a time-lapse of one hour (08:00 to 09:00 h) per experimental tank and treatment. The enzymatic extract was obtained from the complete organisms to determine specific general protease, trypsin, chymotrypsin, amylase and lipase activities. Greater general protease, trypsin and lipase activities were observed in feed at 40% CP. The feeding schedules with greater general protease, trypsin, lipase and amylase activities were found at 14:00 and 20:00 h. Chymotrypsin did not show differences among treatments at CP levels or feeding schedules. Protein level in diets for M. tenellum modified basal digestive enzymatic activity and increased proteolytic and lipolytic activities, while it decreased amylolytic activity as the inclusion of CP level increased in the diet; likewise, the activity was modified by feeding schedule, showing a direct correlation between the increase in digestive enzymatic activity and food offering at the end of the day.

ABSTRACT Previous studies have shown that crustacean feed attractability has an enormous importance, because the consumption, quality and feed conversion rate can be improved, by reducing the time of residence pre-ingestion and the leaching of nutrients. For this reason, different protocols and methods has been developed to measure feed attractability. This study evaluated the use of maze type Y, and rectangular systems to determine the attractant power of a commercial feed on longarm river prawn Macrobrachium tenellum. The Y type maze system without barriers, and with three different types of barriers (with or without access to the area where a commercial feed) was evaluated. Ten prawns were placed in the acclimation chamber of the system at 28°C for 60 min before the start of the experiment. To start the test, commercial feed (20% of prawn biomass) was placed into the system feeding area, then the acclimation chamber was open to allow for the free prawn movement, evaluating the feed attractability by measuring the time for the first “hit”, total number of hits, and the number of prawns which entrances to the feeding area during 15 min. Similar tests were performed with a rectangular type maze system, comparing the atractability results obtained in both systems. The results presented here highlight the importance of the genus behavior and the selection of protocols and systems, as well as the materials used in its maze system construction, for attractability testing in M. tenellum.

ABSTRACT Due to the cost of raw materials, the need to formulate balanced feeds with highly digestible ingredients is indispensable for the aquaculture feed industry. For this reason, the protein in vitro digestibility, assessed by the pH-stat method, of ingredients with potential of using them on the balanced feed for Macrobrachium tenellum, were evaluated. The relative protein digestibility was assessed in twelve feed ingredients, including animal (pork meal, feather poultry meal, prime poultry meal, turkey meal, fish meal, shrimp meal), vegetal (coconut paste, chickpea meal, soybean meal, wheat gluten) and microbial (yeast and Spirulina meal); casein (Hammerstein grade) was used as the reference protein. The highest relative protein digestibility was found in: Spirulina meal (52.6%); following by pork meal (45.6%), and feather poultry meal (39.6%). The lowest digestibilities were found in soybean meal (15.9%), chickpea meal (12.1%), and fish meal (11.6%). The protein digestibility value should be considered for selecting potential ingredients for the formulation of balanced feeds for M. tenellum.

ABSTRACT The present work evaluates the attractant and palatable potential of six ingredients of animal origin in longarm river prawn Macrobrachium tenellum juveniles in a Y type maze system. Ingredients were pelletized for the first bioassay and included in neutral gelatin (in wet base) in the second bioassay. The ingredient to evaluate was placed in one of the Y-maze arms, allowing the free movement of prawn for 15 min. On both bioassays, attractability was evaluated by quantifying the time required for the first prawn to enter the region where the feed was found and the total of prawns which entered that region. In the second bioassay, also evaluated the palatability quantifying the time for the first prawn to have contact with the ingredient, the total of prawns which had contact with it and the time they remained feeding. No significant differences were obtained between treatments in the first bioassay. Significant differences were found in the second bioassay showing that pork meal, fish meal, feather meal and shrimp meal have greater attractability due to the number of prawns attracted, results also show significant differences in palatability, where fishmeal, shrimp meal and pork meal stimulating a higher number of organisms and promoting a longer consumption time.

ABSTRACT In this work we evaluated the essential amino acid profile of muscle Crocodylus acutus and calculated their chemical score of main proteins used in their diet in captivity. The separation and identification of amino acids was carried out by high performance liquid chromatography coupled to a fluorescence detector. The calculation of chemical score was obtained by dividing the value of each essential amino acid between the same amino acid of the reference protein. The lowest value of the relationships is the chemical score. The amino acids present in greater quantities in the tail muscle are glutamic acid, lysine and leucine (16.96, 9.84 and 8.87 g amino acid per 100 g of protein, respectively), whereas histidine, methionine and tryptophan (2.99, 2.93 and 0.59 g amino acid per 100 g of protein) were the lowest. The chemical score obtained results showed that the proteins of animal origin, preferably marine fish and supplemented with terrestrial animals ingredients, including beef liver appear to be the most effective. The incorporation of plant proteins in diets for C. acutus does not appear as a viable alternative due to deficiencies in several essential amino acids such as methionine, lysine and threonine.

ABSTRACT In this work, we studied the digestibility, growth, blood chemistry, and enzyme activity of Nile tilapia (Oreochromis niloticus) juveniles (0.95±0.18 g) using different animal (fish silage meal, whey meal, bovine blood meal, and red crab meal) and plant (extruded bean, extruded chickpea meal, coconut paste, Jatropha curcas meal, and chickpea meal) dietary byproducts. Nine isocaloric diets (321.92±9.10 kcal g−1) were evaluated for 60 days. The highest digestibility of crude protein values for animal and plant sources were obtained for the whey (93.6) and extruded bean meal (90.5) diets, respectively. The final body weight was higher for the red crab and extruded chickpea meal diets, meanwhile the fish silage and red crab byproducts obtained the highest protein efficiency ratio. Hematocrit was similar among the diets of each byproduct source and presented correlation with growth parameters. The highest glucose, cholesterol, and triglyceride values were obtained for fish silage (138.0, 260.5, and 389.0 mg dL−1, respectively) and whey meal (174.5, 242.3, and 284.0 mg dL−1, respectively) groups. A positive correlation was found between the digestibility of crude protein of ingredients and chymotrypsin activity. Oreochromis niloticus is able to better utilize fish silage, whey, extruded bean, and extruded chickpea byproducts, adjusting its digestive physiology. Such ingredients can be used for formulating cheaper and efficient tilapia diets.

Abstract Background. Several studies have addressed the characterization of various digestive enzymes, which is essential to understanding the types, modes of action, and level of activity of these enzymes. Goals: The partial characterization of the digestive proteases was studied in fat snook juveniles (Centropomus parallelus, Poey 1869). Methods: Characterization was performed using electrophoretic and biochemical techniques. Results: Acidic proteases activity (stomach) is higher than alkaline proteases activity (intestine); also, chymotrypsin activity was superior to the trypsin activity. The optimal pH was 2 for stomach proteases with high stability in a wide range of pH 2-8, while the intestinal proteases showed two peaks with activity at pH 8 and 10 with stability at a pH of 8-12. Optimal temperatures were obtained between 45 to 55 °C for stomach and intestine proteases, respectively. Using proteases inhibitors, the presence of an aspartic protease (pepsin) was tested from stomach extracts and diverse serine proteases from intestine extracts. The zymograms showed 5 bands with alkaline proteolytic activity (79.5, 48.9, 37.0, 29.0, and 22.5 kDa), which were highly inhibited with PMSF, SBT1, and ovalbumin. Conclusions. C. parallelus is considered to have a high digestive capacity similar to those reported for other strictly carnivorous marine fish.

Resumen Antecedentes: Diversos estudios han abordado la caracterización de las diversas enzimas digestivas, lo cual es esencial para entender los tipos, modos de acción y nivel de actividad de dichas enzimas. Objetivos. La caracterización parcial de las proteasas digestivas se estudió en juveniles del chucumite (Centropomus parallelus, Poey 1869). Métodos: Se utilizaron técnicas bioquímicas y electroforéticas para la caracterización de proteasas. Resultados: La actividad de proteasas ácidas (estomacales) fue mayor a las proteasas alcalinas (intestinales). Asimismo, la actividad de la quimotripsina fue superior a la actividad de la tripsina. El pH óptimo para las proteasas estomacales fue de 2 con una alta estabilidad en el rango de pH 2-8, mientras que las proteasas intestinales mostraron dos picos con actividad a pH 8 y 10, siendo altamente estables a los pH 8 y 12. Las temperaturas óptimas se obtuvieron a 45 y 55 °C para proteasa estomacales e intestinales, respectivamente. Mediante el uso de inhibidores de proteasas se comprobó la presencia de pepsina en los extractos estomacales y de diversas serinas proteasas en los extractos intestinales. Los zimogramas mostraron cinco bandas con actividad proteolítica alcalina (79.5, 48.9, 37.0, 29.0 y 22.5 kDa), las cuales fueron fuertemente inhibidas con PMSF, SBT1 y ovoalbúmina. Conclusiones: Por lo anterior, se considera que C. parallelus tiene una alta capacidad digestiva similar a otros peces marinos carnívoros estrictos.

RESUMEN Objetivo. La digestibilidad del dsRNA específico para el virus de la mancha blanca (WSSV) por acción de las enzimas del tracto digestivo del camarón Litopenaeus vannamei fue analizada in vitro. Materiales y métodos. Se midió la actividad de enzimas digestivas (proteasa, amilasa, lipasa, ADNasa y ARNasa) en el estómago, la glándula digestiva, el intestino anterior, medio y posterior en juveniles de camarón patiblanco y se evaluó la digestibilidad de ácidos nucleicos ADN, ARN y dsRNA-ORF89 especifico contra el virus WSSV, por análisis electroforéticos y densitometría. Resultados. La actividad enzimática más alta se encontró en la glándula digestiva del camarón: amilasa (81.41%), lipasa (92.60%), proteasa (78.20%), ADNasa (90.85%) y ARNasa (93.14%). Se evidenció la capacidad digestiva del camarón patiblanco contra el ADN, ARN y dsRNA-ORF89 encontrando en la glándula digestiva la mayor digestión (5.11 ng de ADN por minuto, 8.55 ng de ARN por minuto y 1.48 ng de dsRNA por minuto). Conclusiones. La mayor digestibilidad del dsRNA-ORF89, específico contra el virus WSSV, se encontró en la glándula digestiva y la menor en el intestino posterior. Este es el primer informe relacionado con la digestibilidad del dsRNA-ORF89 por las enzimas del camarón patiblanco con potencial importancia terapéutica en el cultivo de camarón para prevenir la enfermedad del WSSV a través del alimento balanceado.

ABSTRACT Objective. The digestibility of specific dsRNA by action of the enzymes of digestive tract of the whiteleg shrimp Litopenaeus vannamei was determined in vitro. Materials and methods. Digestive enzyme activity (amylase, lipase, protease, DNase and RNase) was measured in the stomach, digestive gland, and anterior, middle, and posterior intestine of juvenile shrimp, and the digestibility of DNA, RNA and the dsRNA-ORF89, specific to WSSV, was determined by in vitro assays, as well as electrophoretic and densitometric analyses. Results. The highest enzymatic activity was found in the digestive gland: amylase (81.41%), lipase (92.60%), protease (78.20%), DNase (90.85%), and RNase (93.14%). The highest digestive capacity against DNA, RNA, and dsRNA was found in the digestive gland (5.11 ng of DNA per minute, 8.55 ng of RNA per minute, and 1.48 ng dsRNA per minute). Conclusions. The highest digestibility of dsRNA-ORF89, specific to WSSV, was found in the digestive gland, whereas the lowest digestibility was observed in the posterior intestine. This is the first report regarding the digestibility of dsRNA-ORF89 by whiteleg shrimp digestive tract enzymes, with potential therapeutic importance in shrimp culture to prevent WSSV disease through balanced feed.

Macrobrachium tenellum is a freshwater prawn native from Mexico to Peru, with potential for cultivation. Currently, it is extensively exploited by local fisheries. To understand its chitin requirements, a formulated diet with chitin added (5, 10 15, 20, and 25%) was given to juveniles for 60 days. Growth, survival, and enzyme activity (trypsin, chymotrypsin, lipase, amylase, and chitinase) were measured every 15 days. Highest final weight and specific growth rate resulted from diets with 20% chitin. Poorest performance resulted from diets with 5 and 10% chitin. Chitin in the diet did not have a significant effect on survival. Statistically significant differences in enzyme activity were not found in any treatment.

Food production for aquaculture requires finding other protein sources or ingredients as potential alternatives in the formulation of aquaculture feeds, due to the shortage and high price of protein sources that are most commonly used. The aim of this analysis was to evaluate the relationship between the essential amino acids in 13 types of proteins available in the market with the essential amino acids found in the muscle of four of the most important farmed prawn species of the genus Macrobrachium (M. amazonicum, M. rosenbergii, M. americanum and M. tenellum). The results obtained showed the limiting amino acids of each ingredient for each species, thereby allowing for formulation of commercial foods that meet the nutritional needs to support optimal growth of these prawns in culture. In conclusion, there is a difference in the amino acids most often present as first limiting between sources of animal and plant origin. Thereby, it is possible evaluate complementarities between these sources to achieve an amino acids profile close to that of Macrobrachium species.

La producción de alimentos para la acuicultura requiere la búsqueda de otras fuentes o ingredientes proteínicos como alternativas potenciales en la formulación de piensos para la acuicultura, debido a la escasez y alto precio de las fuentes de proteínas utilizadas con mayor frecuencia. El objetivo de este análisis fue evaluar la relación entre los aminoácidos esenciales de 13 tipos de proteínas disponibles en el mercado con aminoácidos esenciales presentes en el músculo de cuatro de las más importantes especies de langostinos cultivadas del género Macrobrachium (M. amazonicum, M. rosenbergii, M. americanum y M. tenellum). Los resultados obtenidos muestran los aminoácidos limitantes de cada ingrediente para cada especie, lo que permite la formulación de alimentos comerciales que satisfagan las necesidades nutricionales para apoyar el crecimiento óptimo de estos langostinos en cultivo. En conclusión, existe una diferencia entre los aminoácidos que con más frecuencia se presentan como primer limitante entre las fuentes de origen animal y vegetal. De este modo, es posible evaluar complementaciones entre estas fuentes para lograr un perfil de aminoácidos cercano al de las especies de Macrobrachium.

ABSTRACT The objective of our study was to assess the apparent digestibility of plant ingredients in diets for juvenile (50 g) and adult (220 g) Nile tilapia (Oreochromis niloticus). Dietary dry matter and protein apparent digestibility coefficients of four plant-derived feedstuffs (chickpea, maize, high-quality maize protein, and beans) were tested. The beans diet had the lowest apparent digestibility coefficient of dry matter (ADCDM) (69.41%), while no significant differences were detected in ADCDM among the other diets; ADCDM was significantly higher in adults compared with juveniles (77.02 vs. 73.76%). Apparent dry matter digestibility coefficient of ingredients (ADCI) was significantly higher in the chickpea (70.48%) and high-quality protein maize (71.09%) ingredients, and lower in the beans (52.79%) ingredient. Apparent dry matter digestibility coefficient of ingredients was significantly higher in juveniles compared with adults (72.56 vs. 56.80%). The protein digestibility of diet (ADCCP) was significantly higher in the reference diet (93.68%), while the lowest corresponded to the maize (87.86%) and beans (87.29%) diets. Significantly lower apparent digestibility coefficient of protein (ADCICP ) was obtained with the high-quality maize protein (59.11%) and maize (49.48%) ingredients, while higher ADCICP was obtained with the chickpea and beans ingredients (71.31 and 63.89%, respectively). The apparent digestibility coefficient of ingredient crude protein ADCICP was significantly higher in juveniles compared with adults (67.35 vs. 53.46). Digestibility is generally higher in juveniles, and we recommend using chickpea as an ingredient in diets for Nile tilapia.

The scientific interest in the genus Macrobrachium was not only from a biological aspect, but also from economic aspect. This paper analyzed the patents identified in several databases using the keyword Macrobrachium. Patents were selected when a species of Macrobrachium was mentioned in main title. The total number of identified patents was 131, of which Chinese authors and institutions have produced more than 90%. Topics addressed refer to culture technologies (41%), nutrition and feeding (26%), reproduction technologies (19%) and pathological diagnosis and treatments (14%). Patents are mainly directed for M. rosenbergii (71%), M. nipponense (28%) and M. superbum (1%). Until now, it has not been attempts to generate patents to American continent species.

El interés científico por las especies del género Macrobrachium no ha sido solo desde el aspecto biológico, sino también económico. El presente trabajo analiza las patentes detectadas en diversas bases de datos utilizando la palabra clave "Macrobrachium". Se incluyeron las patentes que mencionaran en el título principal a alguna especie de Macrobrachium. Se encontraron 131 patentes, de las cuales instituciones y autores chinos han producido más del 90%. Las temáticas abordadas se refieren a las tecnologías de cultivo (41%), nutrición y alimentación (26%), tecnologías de reproducción (19%), y diagnóstico patológico y tratamientos (14%). Las especies a las que son dirigidas las patentes son M. rosenbergii (71%), M. nipponense (28%) y M. superbum (1%). No se ha publicado ninguna patente para especies del continente americano.

The red claw crayfish Cherax quadricarinatus is native to freshwater habitats of northern Australia and Papua New Guinea. Its high reproductive and adaptive capacity in different environments allows it to be cultivated, where escaped individuals have established wild populations in countries far from their natural range. In the late 90's and beginning of the 21st century, this crayfish was introduced illegally along the coast of southern Jalisco. Mismanagement led to escape and dispersion. Currently there are wild crayfish in the Cajón de Peñas Reservoir and surrounding streams in northern Jalisco, Mexico. The aim of this study was to evaluate the presence of C. quadricarinatus in fisheries in this area of Jalisco and analyze its importance in generating economic benefits for fishermen, comparing these results with those of the fishery for M. americanum, whose fishery is traditional. To catch specimens, traps were set for 24 h in the La Sanja Stream and the Cajón de Peñas Reservoir. The results of the survey showed that C. quadrica rinatus is an important part of the crustacean catch in this area: 32% of the total catch in the stream corresponded to C. quadricarinatus and the rest to M. americanum. While 85% of the catch in the dam corresponded to C. quadricarinatus, only 15% referred to M. americanum. Crayfish fishing in the reservoir is now an important part of the productive activity of local families dependent on fishing. The ecological consequences of wild crayfish proliferation remain to be studied.

La langosta australiana de agua dulce Cherax quadricarinatus es un crustáceo nativo de ríos del norte de Australia y Papua Nueva Guinea. Su alta capacidad de reproducción y adaptación a diferentes ambientes le ha permitido establecer poblaciones silvestres en países lejanos a su área de distribución natural. A fines de los años 90 y comienzo del año 2000, este crustáceo se introdujo ilegalmente a lo largo de la costa del sur de Jalisco, México. La mala gestión motivó la fuga y dispersión de este crustáceo. Actualmente, se encuentran ejemplares en el embalse Cajón de Peñas y arroyos circundantes en el norte de Jalisco. El objetivo de este estudio fue evaluar la presencia de C. quadricarinatus en las capturas realizadas en la zona de Jalisco, y analizar su importancia en la generación de beneficios económicos para los pescadores, en comparación con la pesquería de M. americanum, que es una actividad tradicional. Para la captura de los especímenes, las trampas se colocaron durante 24 h en el arroyo La Sanja y en el embalse Cajón de Peñas. Los resultados mostraron que esta especie es parte importante de la captura de crustáceos en esta área. El 32% de la captura total en el arroyo correspondió a C. quadricarinatus y el resto a M. americanum. Mientras que el 85% de la captura en el embalse, correspondió a C. quadricarinatus y 15% a M. americanum. La pesca de esta langosta en el embalse es un componente importante de la actividad productiva para el sostenimiento de las familias locales. Sin embargo, no han sido aún investigadas las consecuencias ecológicas de su proliferación en los ríos y embalses de la región.