Age, diet, growth and reproduction of a Population of Cobitis paludica (de Buen, 1930) in the Palancar Stream (southwest of Europe, Spain) (Pisces: Cobitidae)

Abstract

A total sample of 99 specimens of the vulnerable fish species Cobitis paludica (de Buen, 1930), was collected on a monthly basis from a tributary of the River Guadalquivir between September 1990 and September 1991. Female longevity was 1 year longer than that of males, the former reaching age-class 5+. The diet of C. paludica consisted mainly of Ostracoda and chironomid larvae, benthic prey of small size and occasionally other resources, such as Macrobiotid eggs spawned during winter. Detritus in gastrointestinal content was scarce, which differs from other populations. Back-calculations of length were performed from scale annuli measurements. The relationship between standard length and scale radius was different for males and females. Females were larger than males of the same age. Both back-calculated length and theoretical length, calculated by applying von Bertalanffy’s model, were larger for females. The relationship between female standard length (SL) and fecundity (F) was log F = ð€€€7.465 + 5.5753 log SL.