Abstract

ANGELES, Beatriz  and  MENDO, Jaime. Growth, fecundity and sexual differentiation of the fine flounder Paralichthys adspersus ( Steindachner ) of the central coast of Peru. Ecol. apl. [online]. 2005, vol.4, n.1-2, pp.105-112. ISSN 1726-2216.

The fine flounder Paralichthys adspersus ( Steindachner ) is a species of great importance for Chile and Peru by its abundance and high commercial value, however little is known about its potential for culture in Peru. This study determine growth and fecundity and analyzes external characters, which permit the sex differentiation in order to know about its potential for culture. Meristic ( 5 ) and morphometric ( 10 ) characters from 150 individuals were measured and analyzed using linear regressions in order to find differences between sex. Age was determined counting annual rings in otoliths and von Bertalanffy growth parameters were estimated using the Ford- Walford plot, meanwhile fecundity of females was estimated counting the number of ovocites of mature gonads ( stage IV ) . The morphometric and meristic characters used in the determination of sexual differentiation, did not show significant differences that can be used in the separation of males from females in a easily and confidentially way. However, it was observed differences in relation to the genital, urinary and anal orifices; females show the 3 orifices separately but males show only two, anal and urogenital orifices. It was found that P. adspersus females growth faster than males. The von Bertalanffy equation for females was Lt= 101.17 ( 1-e -0.140 ( t+ 0.584 ) ) , and Lt= 60.53 ( 1-e -0.253 ( t+ 0.310 ) ) for males. P. adspersus is a partial asynchronic spawner, with mature ovocites between 0.665-0.805mm. The total fecundity was estimated in 2 125 000 eggs per individual and the relative fecundity was 1500 eggs per gram of fish. The potential for culture of this species is discussed comparing growth and fecundity with other flatfish species from natural and cultured stocks.

Keywords : Peru; Paralichthys adspersus; flounder; sexual differentiation; age; growth parameters; fecundity.

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