El presente estudio se desarrolló con la finalidad de analizar el comportamiento de la ictiofauna y sus relaciones alimenticias en tres ríos que desembocan en la laguna de Alvarado, en la costa del Golfo de México y su relación con los parámetros fisicoquímicos a través de un ciclo anual. Se ubicaron dos sitios de muestreo en cada uno de los ríos que desembocan en la laguna, río Papaloapan, río Acula y río Blanco, uno de ellos en su desembocadura hacia la laguna y el otro a 1500 m cauce arriba, en cada sitio de muestreo se registraron los parámetros fisicoquímicos y también se obtuvo la captura de los peces. Los resultados muestran que hay una relación inversa y significativa entre la riqueza de especies y la salinidad, y una relación positiva con la transparencia. Respecto a los peces capturados en el periodo de estudio, se obtuvo un total de 2399 individuos pertenecient...

Length - weight (LW) and standard length - total length (LL) relationships were assessed for 12 fish species caught in the Mulege River estuary (middle Gulf of California), Mexico. Fish were sampled in November 2011 and January 2012, using cast nets and gill nets (mesh size 3 mm). Parameters of the LW and LL relationships were estimated using the log-linear and simple linear regressions. Values of b parameter ranged from 2.39 in Lile stolifera (Jordan & Gilbert, 1882) to 3.16 in Mugil curema Valenciennes, 1836. LL relationships were significantly correlated, ranging 0.851 to 0.999. This study reports for the first time, LL relationships for three species (Ctenogobius sagittula (Günther, 1861), Erotelis armiger (Jordan & Richardson, 1895), and L. nigrofasciata Castro-Aguirre, Ruiz-Campos & Balart, 2002). The information reported here will be useful to generate a baseline for ...

The diet of Girardinichthys multiradiatus (Meek, 1904) in the swamp of Chignahuapan, State of Mexico, was analyzed. The organisms were collected in 2012 covering the climatic dry and rainy seasons. For the analysis of stomach contents, 602 organisms (336 females and 266 males) with sizes between 1.0 and 4.6 cm were studied. The results showed a consumption of 13 food types, of which cladocerans and copepods were the most consumed in both seasons. Similar data showed ontogenic factors. The niche amplitude, according to the Levins index, was low for both sexes due to the high consumption of cladocerans, while the Zander Main Food Index, showed cladocerans and diptera as essential prey in their diet. These data change slightly by climatic season, since it depends on the environmental characteristics of the system, as well as the composition and abundance of the resources consumed by this sp...