Distribución espacio-temporal de la idiofauna del no Cutzamala, Michoadn, México

Abstract

The fuh community in fue Cutzamala river, Mexico was sampled six times between December 1985 aud November 1986; it showed dumges in pattems of distributien and abundance according to rainfall regime. Hybopsis boucardi, Poecilia IJutlen atJ.d Jlyodon whitei were dominoot during fue dry seascn; in fue Tainy seasan, juvenil. es af P. butleri comprised 80 % afthe total capture. Diversity and evenness values increased in middle and low portions ofthe river during the dry season; en the other hand these paramfters showed hi1i!J;:l values in headwaters during rainy =00.. Three fish assemblages were identified with c1assification mdhods: (1) in the high sectioo of the river; oo1y Cyprinds were found, (2) Astyanax fasciatus, I. whitei and P. butlen located in the middle seruoo and (3) Heterandria bimaculata, I. balsunus, Poeciliopsis balsas and Ctenopharyngodofl idellus in the low secticn. There may be a shift of the second assemblage to the high section early after af the spawning season.