Abstract

ROMAN-VALENCIA, César. Alimentación y reproducción de Creagrutus brevipinnis (Pisces: Characidae) en Alto Cauca, Colombia. Rev. biol. trop [online]. 1998, vol.46, n.3, pp.783-789. ISSN 0034-7744.

Stomach contents and reproduction were studied in characid fish (C. brevipinnis)collected in the Vieja River Basin, Alto Cauca, Colombia (July 1995 and December 1996); the 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 third level predator in the trophic web; it feeds from 06:00-18:00 hr ; the results indicate seasonal variation in feeding activity (F= 19.04 P< 0.0001) and a negative correlation between stomach weight and voracity indexes; in the reproductive season food in take 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).

Keywords : Trophic; ecology; feeding; reproduction; Creagrutus brevipinnis; tropical fishes.