Alimentación de Chirostoma humboldtianum (Valenciennes); (Pisces: atherinopsidae) en el estanque JC en Soyaniquilpan, Estado de México

the smalls like fishes are endemic fishes in the central region of mexico, and they have been to eat since prehispanic time, nowadays, the volume catch has decreased because their overfishing and habitat pollution so, it is very important to study these populations remains to know about their ecological and diet require and to express any alternatives to their conservation. our goals in this study were; to determinate what kind of groups food chirostoma humboldtianum foods into jc pond in soyaniquilpan, state of mexico and to know about physics and chemical parameters water variations. we took six monthly sampling to december of 2001 to may of 2002. we registered temperature, depth, transparency, conductivity, muddy, ph, oxygen, hardness and alkalinity. the fishes were captured in a mesh of measure ring 25 meters with 8.0 millimeters aperture and they were fixed with formalin to 10 %. the food content was identified using specializing keys. the volumetric and frequency methods were used to determinate food groups percentage. the water was warm, muddy, concentration dissolute oxygen medium, moderate hardness. chirostoma humboldtianum consumed 21 groups of organisms keratella trichocerca, asplanchna, bosmina outstanding further copepod, corixids and chironomids. frequency method showed cyclops and keratella like preferential foods.