Ictioplan cton en la ciénaga de ayapel, río san jorge (Colo mbia): Cambios espacio-temporales

Abstract

Ichthyoplankton surveys were conducted in eight sampling sites in Ayapel Floodplain Lake during a one hydrological periods. We used a conical net with a diameter of 35 cm opening with a flowmeter installed at the mouth of the net to obtain the volume of filtered water. The larvae were grouped according to their taxonomic order and development phase. We captured 1321 individuals grouped into 6 species and 27 morphotypes. The densities were between 0.29 and 576 individuals/m- 3. Sampling sites near to the San Jorge River influence showed the highest densities. Silurifoms and Characiforms were the most important fish orders in the samples and their densities were associated with the physical factors such as rains, water level, the conductivity in the lake and the floods of the San Jorge River. The last factor was responsible for the flooding of lateral areas, which leads to increase nutrients and microhabitats that provide food and shelter for the development of individuals in the early periods of its ontogenic development.