Se analizaron 321 ejemplares de la corvina Plagioscion squamosissimus entre julio de 2003 a junio de 2004 con la finalidad de obtener la relación longitud – peso, proporción por sexos, época de desove, talla media de madurez (longitud total), y composición de su ítem alimenticio. La relación longitud – peso no mostró diferencias significativas entre sexos, proponiéndose la ecuación conjunta PT = 0.0057708 LT 3.21 para la especie. La proporción sexual se ajustó a la proporción 1:1. La talla media de madurez en machos fue de 29.6 cm y para hembras de 31.2 cm. Las variaciones del índice gónadosomático (IGS) evidenciaron que la especie se reproduce durante todo el año, aunque con mayor frecuencia entre setiembre y octubre (época de vaciante e inicios de creciente) y en menor cuantía entre febrero y marzo (mediados a fines de creciente). La dieta estuvo conformada fundam...

El conocimiento de la biología y pesquería de una especie explotada es esencial para un manejo racional y una producción sostenida. De febrero a diciembre de 1994 se colectó información de una de las especies más importantes por los volúmenes de desembarque en Ucayali, el boquichico (Prochilodus nigricans). Se analizaron aspectos biométricos (relación longitud total - peso total: LTPT) y reproductivos (proporción por sexos, época de reproducción, tallas de madurez) de esta especie. La relación LT-PT no mostró diferencias significativas entre las regresiones de machos y hembras (análisis de variancias residual F0,05) proponiéndose el empleo de una ecuación conjunta para la especie de la forma PT = 0,0211 LT 2,8592. La proporción sexual total no mostró diferencias significativas (χ 2 0,05) al asumir una relación 1:1. El análisis de la progresión de los estadios de ma...

In the study, 321 individuals of Plagioscion squamossissimus were analyzed from July 2003 to June 2004 to obtain the length - weight relation, sex ratio, egg-laying seasonality, mature size, and composition of their diet. The length - weight relation did not show significant differences between sexes, and therefore the combined equation PT = 0.0057708 LT 3.21 is proposed for the species. The sex ratio was close to 1:1. The mature size was 29.6 cm in males and 31.2 cm in females. Variations in the gonad-somatic index (IGS) showed that this species reproduce throughout the year, but more frequently between September and October (end of dry season) and between February and March (mid and end of rainy season). The diet of the species was mainly composed by fishes.

The knowledge of biology and fishery is essential for an adequate management and a sustained production. Boquichico (Prochilodus nigricans) is one of the principal components of the fish catch in Ucayali. From February to December, 1994, the sex proportion, reproduction season, mature length and Total length/Weight ratios (LT-PT) of boquichico were recorded and analyzed. The LT-PT between males and females, suggests the use of a unique PT = 0,0211 LT 2.8592 model for both sexes. Sexual proportion was essentially 1:1 by the χ 2 0,05 criterion. Maturity stages progression analyses confirm that the reproduction of boquichico occurs during the Ucayali river flood (October-January). Calculated mature length were 24,5 cm and 26,1 cm for males and females, respectively.

Mylossoma duriventre "palometa" es un pez de la familia Characidae, explotado comercialmente para consumo humano directo en la región de Ucayali, Perú. El objetivo del estudio fue ampliar los conocimientos reproductivos de la especie estimando su fecundidad. Se recolectaron 49 ejemplares en estadio IV y V de madurez que fueron desembarcados en el puerto de Pucallpa durante el ciclo reproductivo 2011-2012. Se registró la longitud (LT) y peso (PT) total de cada pez, así como el peso de las gonadas (PGón). Se tomaron submuestras de las gónadas para el conteo de los ovocitos y determinación de la fecundidad, aplicando la ecuación de regresión lineal simple F=a+bx, donde F = fecundidad, x = longitud total, peso total o peso del ovario, y a y b son los coeficientes de la regresión (a = intercepto, b = tasa de incremento de la fecundidad con respecto a las variables de análisis). La ...

Mylossoma duriventre «Silver Mylossoma» is a fish of the family Characidae, commercially exploited for human consumption in the region of Ucayali, Peru. The aim of the present study was to improve the reproductive knowledge of the species in relation to fecundity. Forty nine specimens were collected from landings in Pucallpa during the 2011-2012 reproductive cycle. Measurements of total length (LT), total weight (PT) and the weight of gonads (PGon) of each fish were recorded. Subsamples of gonads were taken for oocyte counting to determine fecundity applying the simple linear regression equation F = a + bx, where F = fecundity, x = total length, total body weight or ovarian weight, a is the intercept and b the rate of increase in fecundity in relation to the variables in the study. The mean absolute fecundity was estimated in 68 280 oocytes which corresponds to an average LT of 21.3 cm...

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...