LENGTH-WEIGHT RELATIONSHIP OF RUBIO (Salminus affinis Steindachner, 1880) IN THE SINU RIVER BASIN, COLOMBIA

Objective. To estimate the length?weight relationship of rubio in the Sinu river basin, as a contribution to the management of their fishery. Materials and methods. Between January 2000 and August 2005, 122 individuals with sizes between 9.3 and 63.0 cm total length (TL) and weight (WT) ranged between 6.6 to 3966.0 g were collected. Resultados. The length?weight relationship was: TW = 0.005 (± 0.03) TL3.19 (± 0.02), positive allometric growth coefficient (b), and correlation coefficient of 0.99. The growth coefficient varied between 3.34 y 3.21 without statistically significant differences (p£0.05). The condition factor oscillated between 0.003 y 0.005, without statistically significant differences (p£0.05). We found a correlation among the condition factor, the level of the Sinu river, and spawning season of the rubio, which extends from March to September. Conclusions. Rubio have adapted to the new conditions of the Sinu river as determined by lack of significant differences in size and weight.