Acta Biológica Colombiana (Jan 2000)
Aspectos ecológicos de la fauna íctica dominante en la Laguna Yahuarcaca, Leticia (Amazonía colombiana)
Abstract
ABSTRACTFour fish samplings taken during one year in the Laguna Yahuarcaca, located close to Leticia(Colombia) and formed by meanders of the Amazon River, were analyzed. Two of the samplingswere taken during the high water period, one during the lowering of the waters and one duringthe low water period. The samplings were used to characterize the ichthyofauna and todetermine the alimentary and reproductive aspects of the species analyzed. 5856 specimenswere captured, included in seven orders, 23 families, 102 genera and 134 species. 57 speciesare new reports for the Colombian Amazonian fish fauna. The most abundant orders (bynumber of individuals) were Characiformes, Siluriformes, Perciformes. The most abundant familieswere Auchenipteridae, Doradidae, Serrasalmidae, Loricariidaeand Cichlidae. The fish compositionchanged through the different samplings; the highest number of species was captured duringthe high and lowering water periods, while the lowest number of species was registered for thecaptures done during the low water period. The trophic analysis was done with the five mostabundant species; it was found that the alimentary preferences varied depending upon thehydraulic pulse. The species analyzed are included in the families Curimatidae(Potamorhina altamazonicaand Psectrogaster rutiloides), Pimelodidae (Callophysus macropterusand Pimelodus blochii)and Auchenipteridae(Centromochlus heckelii). Both curimatids are detritophagus, C. macropterusis scavanger, eating pieces of fish remains, P. blochiiconsumes seeds and fruits, and C. heckeliiisinsectivorous. Concerning reproductive aspects, none of the specimens was mature. This wasprobably due to the fact that reproduction takes place during the rising water period andthis period was not sampled for this aspect.
