Studies on the potential fecundity of chiochío, Psectrogaster rutiloides, are scarce despite this is one of the main fish species for small scale commercial and subsistence fishing catch in the Ucayali basin (Peru). A total of 74 female specimens on maturity stage IV were collected in October and November 2009. Total length, body weight, and gonad weight were recorded, and fecundity was assessed through the number of oocytes by the gravimetric method. Body length and weight were 15.2 ± 1.9 cm and 68.5 ± 24.7 g respectively, and the weight of gonads was 12.5 ± 5.3 g. The estimate number of oocytes was 45 058 ± 20 770. The relative fecundity varied from 1194 to 6619 oocytes per cm of body length, from 302 to 1202 oocytes per gram of body weight, and from 2654 to 8739 oocytes per gram of gonad weight. The regression analysis showed that gonad weight is a suitable predictor of the fecun...

Studies on the potential fecundity of chiochío, Psectrogaster rutiloides, are scarce despite this is one of the main fish species for small scale commercial and subsistence fishing catch in the Ucayali basin (Peru). A total of 74 female specimens on maturity stage IV were collected in October and November 2009. Total length, body weight, and gonad weight were recorded, and fecundity was assessed through the number of oocytes by the gravimetric method. Body length and weight were 15.2 ± 1.9 cm and 68.5 ± 24.7 g respectively, and the weight of gonads was 12.5 ± 5.3 g. The estimate number of oocytes was 45 058 ± 20 770. The relative fecundity varied from 1194 to 6619 oocytes per cm of body length, from 302 to 1202 oocytes per gram of body weight, and from 2654 to 8739 oocytes per gram of gonad weight. The regression analysis showed that gonad weight is a suitable predictor of the fecun...

A factorial experiment was conducted to evaluate the effect of diets with two levels of protein (25 and 35%) and three levels of digestible energy (2.3, 2.5, and 2.7 kcal/g) on the “gamitana” Colossoma macropomum in terms of body weight gain (WG), food conversion (FC), retained energy (RE), and protein efficiency ratio (PER). Diets contained anchovy and soybean meal as protein sources, and yellow corn, wheat bran, and brewery bran as energy sources. There were highly significant interactions (p<0.01) between protein concentration and digestible energy on the “gamitana” growth. In diets with 25% protein, the increase of digestible energy significantly enhanced WG, FC, RE, and PER, where the level of 2.7 kcal/g had the best performance. However, in diets with 35% protein, only the 2.7 kcal/g level showed good results. It can be concluded that the best response was obtained with ...

Se llevó a cabo un experimento factorial para examinar el efecto de la interacción de dos niveles de proteína (25 y 35%) y tres niveles de energía digestible (2.3, 2.5 y 2.7 kcal/ g de alimento) en la dieta sobre la ganancia de peso (GP), conversión alimenticia (CA), energía retenida (ER) y el cociente de eficiencia proteica (REP) en la gamitana (Colossoma macropomum). En la composición de las dietas se empleó harina de anchoveta y harina de torta de soya como fuentes de proteína y maíz amarillo duro, subproducto de trigo y subproducto de cervecería como fuentes de energía. Se encontraron interacciones altamente significativas (p<0.01) entre la energía digestible y la proteína. En las dietas con 25% de proteína, el incremento del nivel de energía digestible mejoró significativamente la GP, CA, ER y la REP, siendo la mejor respuesta con 2.7 kcal/g. Sin embargo, para el...

Se presenta una clave de identificación para géneros de bivalvos amazónicos basada en caracteres de las partes blandas y de la concha. Se indican detalles de seis géneros (Castalia, Diplodon, Mycetopoda, Anodontites, Lcyla y Bartlettia).

Se presenta una lista taxonómica preliminar de 26 especies de bivalvos de agua dulce pertenecientes a 18 géneros y 5 familias de bivalvos de agua dulce.

Se presenta una clave de identificación para géneros de bivalvos amazónicos basada en caracteres de las partes blandas y de la concha. Seindican detalles de seis géneros (Castalia, Diplodon, Mycetopoda, Anodontites, Lcyla y Bartlettia).

Se presenta una lista taxonómica preliminar de 26 especies de bivalvos de agua dulce pertenecientes a 18 géneros y 5 familias de bivalvos de agua dulce.