The effect of the chlorophytes Scenedesmus sp and Chlorella sp used as feed on the growth of the native cladoceran Ceriodaphnia sp were studied. Three treatments with three repetitions for each chlorophyte were used: T1 = 5 ml.L-1 (25 x 106 cells), T2 = 10 ml.L-1 (50 x 106 cells) and T3 = 15 ml.L-1 (75 x 106 cel). The physical and chemical characteristics of the water in the containers varied between 28.4 and 28.6 °C, pH between 6.57 and 7.36 and the dissolved oxygen between 6.34 and 6.66 mg/l between treatments. The results showed that Ceriodaphnia sp prefers the Chlorella sp microalgae, where diets with a concentration of 10 ml.l-1 (50 x 106 cells) were better than the other diets.

The effect of the chlorophytes Scenedesmus sp and Chlorella sp used as feed on the growth of the native cladoceran Ceriodaphnia sp were studied. Three treatments with three repetitions for each chlorophyte were used: T1 = 5 ml.L-1 (25 x 106 cells), T2 = 10 ml.L-1 (50 x 106 cells) and T3 = 15 ml.L-1 (75 x 106 cel). The physical and chemical characteristics of the water in the containers varied between 28.4 and 28.6 °C, pH between 6.57 and 7.36 and the dissolved oxygen between 6.34 and 6.66 mg/l between treatments. The results showed that Ceriodaphnia sp prefers the Chlorella sp microalgae, where diets with a concentration of 10 ml.l-1 (50 x 106 cells) were better than the other diets.

El objetivo del presente estudio fue evaluar la influencia de las clorofitas en el crecimiento poblacional del rotífero Brachionus calyciflorus. El cultivo experimental se realizó en nueve recipientes de polietileno de 4 L con volumen útil de 800 mL de agua filtrada donde se sembraron diez rotíferos Brachionus calyciflorus por recipiente y fueron alimentados con microalgas a una concentración de 6 x 106 cel mL-1: Chlorella sp. (Ch), Scenedesmus sp. (Sc) y Chlorella sp. + Scenedesmus sp. (Ch + Sc), durante 15 días de cultivo. Diariamente se realizó el conteo de los rotíferos y se evaluaron los parámetros de crecimiento poblacional. Los valores medios de: temperatura fueron de 27,7 ± 0,31 oC, oxígeno disuelto de 4,9 ± 0,05 mg L-1 y pH de 6,6 ± 0,22. Los valores poblacionales más elevados en los rotíferos se obtuvieron alimentando con la mezcla de Chlorella sp. + Scenedesmus ...

The objective of the present study was to evaluate the influence of chlorophytes on the population growth of the rotifer Brachionus calyciflorus. The experimental culture was carried out in nine 4 L polyethylene containers with a useful volume of 800 mL of filtered water where ten Brachionus calyciflorus rotifers were planted per container and fed with microalgae at a concentration of 6 x 106 cel mL-1: Chlorella sp. (Ch), Scenedesmus sp. (Sc) and Chlorella sp. + Scenedesmus sp. (Ch + Sc), during 15 days of culture. Rotifers were counted daily and population growth parameters were evaluated. The mean values of: temperature were 27,7 ± 0,31 o C, dissolved oxygen 4,9 ± 0,05 mg L-1 and pH 6,6 ± 0,22. The highest population values were with the mixture of Chlorella sp + Scenedesmus sp (yield of 1250 ± 523 ind mL-1, growth rate of 1.0 ±, 0,1 day, doubling time of 0,7 ± 0,1 day and the ma...

This work was carried out in the lower basin of the Nanay River (Loreto) during the months of September 2021 to August 2023, aiming to evaluate the feeding regime of three species of ornamental fish (Pterophyllum scalare, Biotodoma cupido and Petitella georgiae) and their relationship in hydrological periods of flooding and ebb, and to determine the composition of the stomach contents and preferential diets of said fish, the specimens were captured with a one inch fry net, they were collected in plastic buckets with 10% formalin, then they were washed and changed to buckets with 70% alcohol, in the laboratory they were weighed on a digital scale and measured with the help of an ichthyometer until they were eviscerated by the urogenital part, to extract the stomachs, they were weighed on an analytical balance, then the stomach contents were emptied into eppendorf tubes with 10% alcohol, t...

El objetivo del estudio fue conocer la distribución espacial y temporal de insectos acuáticos en 10 quebradas de llanura amazónica, ubicadas dentro del área de influencia del eje carretero Iquitos-Nauta (Loreto, Perú). Las colectas fueron realizadas en dos zonas de muestreo con diferentes vías de acceso, grado de influencia antrópica y dimensión de las quebradas, que fueron denominadas: ZM 1 y ZM 2; y, durante tres distintos periodos hidrológicos del año: vaciante, seca y creciente. Se evaluó la riqueza, abundancia, diversidad y dominancia de estos organismos; así como los niveles de pH, temperatura (ºC), oxígeno disuelto (mg/l) y conductividad eléctrica (μS/cm) de la columna de agua de cada quebrada. Los resultados reportan una riqueza total de 63 familias y 4771 individuos; de las cuales las familias Leptophlebiidae, Caenidae, Libellulidae, Hidrophilidae, Elmidae, Hydro...

This study aimed to determine the spatial and temporal distribution of aquatic insects in 10 streams of the Amazon lowlands located within the area of ​​influence of the Iquitos-Nauta highway (Loreto, Peru). Samplings were made in two zones with different access roads, anthropic influence and stream sizes, which were named: ZM 1 and ZM 2; and, during three distinct hydrological periods: draining season, dry season and rising season. Richness, abundance, diversity, and dominance of aquatic insects; as well as water pH, temperature (ºC), dissolved oxygen (mg/l) and electrical conductivity (μS/cm) levels of each stream were recorded. Results report a total richness of 63 families and 4771 individuals; of which the families Leptophlebiidae, Caenidae, Libellulidae, Hidrophilidae, Elmidae, Hydropsychidae, Polycentropodidae, Tipulidae, Ceratopogonidae and Chironomidae, are widely distribu...