Characteristics of the european bitterling rhodeus amarus (cyprinidae) in the rihios river, Greece

Abstract

We sampled the population of the European bitterling Rhodeus amarus (Bloch, 1782) from the Rihios River (Greece) monthly between September 1997 and January 1999. The overall sex ratio of females to males was 1:2.14 and was statistically different from unity. The total length of the individuals caught varied from 12 to 83 mm. The population of the Rihios River grew allometrically and had a five-year life cycle. The parameters of the von Bertalanffy growth curves were estimated as L∞= 120.25 mm, k= 0.86/year, and t0= 0.22 years. The condition factor and the gonadosomatic index indicated that reproduction occurred around April-June. Fecundity was low with a few but relatively large eggs produced. Natural mortality was 0.60/year. The diet of bitterling consisted of algae, insects, crustaceans, and organic and inorganic material. © 2003, Copyright Taylor & Francis Group, LLC.