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Reproduction of the duck catfish Ageneiosus ucayalensis in a ria river system
V A Oliveira1, M A P Ferreira2, R M Rocha3
1Graduate Programme in Zoology, Universidade Federal do Pará-Museu Paraense Emílio Goeldi, Rua Augusto Corrêa, N° 1, Bairro Guamá, CEP: 66075-110, Belém, Pará, Brazil.
Abstract:
A total of 1006 duck catfish Ageneiosus ucayalensis were collected from a ria river system of eastern Amazonia, of which 733 were females and 273 males, a sex ratio 2·69:1. Condition factors of males were higher than those of females and size at first sexual maturity (L50 ) was 12·8 cm for females and 11·8 cm for males. The relative frequency of mature specimens and gonad condition indices indicate that the breeding season is short and coincides with the rainy season.
