Alimentación y reproducción de Creagrutus brevipinnis (Pisces: Characidae) en Alto Cauca, Colombia

Abstract

Stomach contents and reproduction were studied in eharacid fish (e. brevipinnis)collected in the Vieja River Basin, Alto Cauea, Colombia (July 1995 and December 1996); ¡he temperature in the region was 21.7°C (18.70- 24.40°C), pH was neutral and water oxygen content high (8 ppm); C. brevipinnis is nonmigratory and sympatric with other 30 fish species. The fish is insectivorous and specializes on Diptera (Simuliidae) and Ephemeroptera; being a thírd level predator in the trophic web; il feeds from 06:00-18:00 hr; the results indicate seasonal variation in feeding activity (F: 19.04 P< 0.0001) and a negative correlatíon between stomach weight and voracity indexes; in ¡he reproductive season food in talce is low; the ovaries mature primarily between May and January ; fecundity is low (613 oocytes) and the eggs are of small (diameter 0.6254 mm) ; the sex ratio is 1:1 (X2: 2.56 P< 0.1 df : 1) and the mean size at maturity is 4.0 cm (standard length).