The study was carried out at Pedra do Cavalo fish farm, Cachoeira, Ba, with weekly collections in the months of September and November, totaling 6 samples. Sampling time refers to the development time of the larvae to the stage of the fingerlings, when they are ready to be marketed. The physical-chemical and biological parameters of the water were collected as: temperature, dissolved oxygen, pH, electrical conductivity, ammonia, nitrite, total phosphorus and chlorophyll a of three tanks and drainage and water channels for comparison between locations. The zooplanktonic colonization was also recorded and identified at species level for cladocerans and rotifers groups and at the large group level for the copepods, the collection of these organisms was done through a plankton net. Some physico-chemical parameters were collected in situ with the use of a multiparameter probe. Water samples were collected for analysis of ammonia, nitrite, phosphorus and chlorophyll a in the laboratory. The sites studied were classified as supereutrophic and hypereutrophic according to the Trophic State Index. A dominance of the rotifer group was verified in the sampled places, a group frequently associated with eutrophication of water bodies. Among copepods, nauplii and copepodite forms were more frequent than adult forms. | O estudo foi realizado na estação de piscicultura da Pedra do Cavalo, Cachoeira, BA, com coletas semanais nos meses de setembro e novembro, totalizando 6 coletas, O tempo de amostragem refere-se ao tempo de desenvolvimento das larvas até o estágio juvenil, quando estes já estão prontos para serem comercializados. Foram coletados parâmetros físico-químicos e biológicos da água como: temperatura, oxigênio dissolvido, pH, condutividade elétrica, amônia, nitrito, fósforo total e clorofila-a de três tanques e dos canais de drenagem e de captação da água, para comparação entre os locais . A colonização zooplânctonica também foi registrada e identificadas em nível de espécie para os grupos de cladoceros e rotíferos e nível de grandes grupos para os copepodes, sendo a coleta desses organismos feita através de uma rede de plâncton. Alguns parâmetros físico-químicos foram coletados in situ com a utilização de uma sonda multiparâmetros. Foram coletadas amostras de água para analise de amônia, nitrito, fósforo e clorofila-a em laboratório. Os locais estudados foram classificados como supereutróficos e hipereutroficos de acordo com o Índice de Estado Trófico. Foi verificado uma dominância do grupo Rotífera nos locais amostrados, grupo frequentemente associado à eutrofização de corpos hídricos. Entre os copépodas, as formas de náuplio e copepodito foram mais frequentes que as formas adultas.

"Se llevó a cabo un estudio experimental en tres fases, a fin de evaluar el efecto de alimento natural exógeno sobre la respuesta productiva, condición nutricional e inmune, y calidad post cosecha del camarón blanco del pacifico Litopenaeus vannamei, durante la pre-engorda superintensiva. En la primera fase se evaluaron 4 grupos zooplanctónicos (rotiferos, copepodos, Artemia e insectos acuáticos) en 4 densidades, sobre el desempeño productivo y calidad del agua del sistema. En la segunda fase se evaluaron dos medios de cultivo alternativos, uno agrícola y otro acuícola, para la producción de las microalgas Nannochloropisis oculata y Chaetoceros muelleri, las cuales a su vez fueron evaluadas como alimento para Brachionus rotundiformis, Acartia sp. y Calanus pacificus. En la tercera fase se evaluó la sustitución parcial y total del alimento formulado, por alimento natural exógeno (insectos), en la respuesta productiva, condición nutricional e inmune y calidad post cosecha de juveniles de camarón, EI medio a base de fosfato monoamonico fue similar al medio Guillard F2 en la producción de biomasa de N. oculata. Sin embargo, microalgas en un medio con Nutrilake generaron mayor producción de rotíferos (l32.5±6.35 r/ml) y fecundidad (1.25±0.09 huevos/hembra) comparado con el control (111.5±9 .29 r/ml y 0.67±O.12 huevos/hembra, respectivamente). Se encontró que la inclusión de alimento natural exógeno tuvo efectos positivos en la respuesta productiva del camarón y no hubo efectos adversos significativos en la calidad del agua. Camarones alimentados con insectos acuáticos a1canzaron 4.97±0.50 g, con una sobrevivencia de 86.67%. Camarones alimentados con rotíferos alcanzaron 3.40±0.07 g, con una sobrevivencia de 92.42%, mientras que el control alcanzo 2.18±0.31 g, con sobrevivencia de 62.12%. La sustitución parcial al 50% del alimento formulado por insectos acuáticos, resulto en biomasa similares al control, una mejor sobrevivencia y un factor de conversión de alimento significativamente menor (l.44±0.06). Se presentó una tendencia en la que la cantidad de hemocitos se incrementa en función a la cantidad de alimento natural. Los conteos mas bajos de hemocitos y mas altos de profenol oxidasa se presentaron en el tratamiento con alimento artificial. Se estableció que hay una mayor cantidad de proteína y menor cantidad de glucosa, colesterol y triglicéridos en la hemolinfa de camarones que recibieron alimento natural..." | "A three-phase experimental study was conducted to evaluate the effect of natural feed on the production response, nutritional an immune condition, and post harvest quality of white shrimp, Litopenaeus vannamei, in a super intensive nursery phase. In the first phase 4 zooplankton groups (rotifers, copepods, Artemia and aquatic insects) were evaluated at 4 densities, in terms of productive performance of shrimp fed on them, and water quality of the system. In the second pha e, 2 alternative mediums: 1 agricultural and 1 aquaculture fertilizer, were evaluated for the production of the micro algae Nannochloropisis oculata and Chaetoceros muelleri, which were also evaluated as feed for Brachionus rotundiformiss, Acartia sp. and Calanus pacificus. In the third phase, the partial and total replacement of formulated feed by exogenous natural feed (insects) was evaluated in terms of production response, nutritional and immune condition and post harvest quality of shrimp. The use of mono ammonic phosphate medium for the production of N. oculata generated similar results to the use of Guillard F2. Microalgae in a Nutrilake fertilized system produced higher number of rotifers (132.5±6.35 r/ml) and fecundity (1.25±0.09 eggs/female) when compared with the control (1 11.5±9.29 r/ml y 0.67±0.12 eggs/female, respectively). Inclusion of natural exogenous food had a positive response in terms of production, with no apparent negative effects in terms of water quality. Shrimp fed with aquatic insects attained a final test weight of 4.97±0.50 g, and survival of 86.67%. Rotifer fed shrimp had a mean final weight of 3.40±0.07 g, and a survival of 92.42%. Mean [mal weight for control shrimp was 2.18±0.31 g (survival = 62.12%). A 50% formulated feed substitution for aquatic insects resulted in a similar final biomass to the control, better survival and a significantly lower food conversion rate (l.44±0.06). Hems cite count increased as the level of natural feed increased in the treatments. This is a reflection of the immune state of the organism. Low hem cite and high prophenol oxidase levels were present in the control (artificial feed) treatment. There was a higher protein and lower glucose, cholesterol and triglyceride levels in the hem lymph of shrimp receiving natural exogenous feed..."

Introduction: Sludge Biotic Index (SBI) is one of the most used indices for the characterization of the community of microorganisms present in the activated sludge of wastewater treatment systems. However, this index takes into consideration only the density of the predominant functional groups of protozoa that inhabit this sludge. Objective: To evaluate whether the SBI value can be directly related to the number of protozoos and metazoos species found in the activated sludge of two wastewater treatment systems. Methods: This study was carried out on the wastewater generated by the San Vicente de Paul Hospital in Heredia Province, Costa Rica, during the months of February, March, and April 2022. Physicochemical, environmental, operational, and biological parameters were analyzed in a total of 36 samples from a Conventional activated sludge wastewater treatment system and from a Membrane Bioreactor (MBR) (n = 18 for each treatment system). Results: All the parameters evaluated are related to the abundance of microorganisms in the samples analyzed. The SBI value had an important effect on the number of organisms and can be related to the performance of the treatment system in terms of the percentage of Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) removal, especially for the MBR system. Conclusions: The SBI can be improved so its calculation not only considers functional groups but also includes genus and species of protozoos and metazoos present in the activated sludge. Which in turn would refine its bioindication potential by being more specific in terms of abundance, behavior and specific requirements of each species. | Introducción: El Índice Biológico de Lodos (IBL) es uno de los índices más utilizados para la caracterización de la comunidad de microorganismos presentes en el lodo activado de los sistemas de tratamiento de agua residual. Sin embargo, este índice toma en consideración únicamente la densidad de los grupos funcionales de protozoos predominantes que habitan este lodo. Objetivo: Evaluar si el valor del IBL puede relacionarse directamente con la cantidad de las especies de protozoos y metazoos encontradas en el lodo activado de dos sistemas de tratamiento de aguas residuales. Métodos: Esta investigación se realizó en las aguas residuales generadas por el Hospital San Vicente de Paul en la provincia de Heredia, Costa Rica, durante febrero, marzo y abril del 2022. Se analizaron parámetros fisicoquímicos, ambientales, operacionales y biológicos en un total de 36 muestras de un sistema de tratamiento por lodos activados Convencional y de un Biorreactor de Membrana (MBR) (n= 18, para cada sistema de tratamiento). Resultados: Todos los parámetros fisicoquímicos, ambientales y operacionales evaluados se encuentran relacionados con la abundancia de microorganismos en las muestras analizadas. El valor del IBL ejerció un efecto importante en la cantidad de organismos, y puede relacionarse con el desempeño del sistema de tratamiento en cuanto al porcentaje de remoción de la Demanda Bioquímica de Oxígeno (DBO) y Demanda Química de Oxígeno (DQO), sobre todo para el sistema MBR. Conclusiones: El IBL puede ser mejorado de manera que en su cálculo no solo considere grupos funcionales, sino que se incluya el género o especie de los protozoos y metazoos presentes en el lodo activado. Lo cual a su vez afinaría su potencial de bioindicación al ser más específico en cuanto a la abundancia, comportamiento y requerimientos específicos de cada especie.