ASPECTS OF REPRODUCTION AND FEEDING OF THE RAINBOW TROUT SALMO GAIRDNERI IN CONCHI RESERVOIR, ANTOFAGASTA, CHILE.

Abstract

No Information is available on biológica! aspects of the rainbow trout (Salmo gairdneri) introduced lo northern Chile.
This paper presents observations on reproduction and feeding of trout collected in this región. Rainbow trout were
captured in the Conchi reservoir by trammel netting at depths of 5 to 25 m; 225 specimens were obtained.
The relation between total length and body weight was given by the expression: W = 0.01790 x L2 88. The period of
reproductive activity was found to be from July to September when the water temperature droped to 6o to 9°C. More
females were collected than males (1.38 F./M.). Average fecundity for females was 3228 ovules for length between 33
and 51 cm. The relation between total length and fecundity was given by the expression: F = 4.0468 x L1 78.
The gastric contents analysis showed that 5. gairdneri in Conchi reservoir ate the abundant amphipod Hyalella (88.99%)
and also Insecta (9.11%), Bivalvia (0.56%), Hirudinea (0.35%) and Gastropoda (0.01%).