GROWTH AND MORTALITY OF THE YALUA FISH (Cyphocharax magdalenae Steindachner, 1878) IN THE SINÚ RIVER, COLOMBA

Growth and mortality parameters of Yalúa (Cyphocharax magdalenae Steindachner, 1878) were estimated based on length frequency data (ELEFAN) from January to December 2000. Total length (TL), fork length (FL) and standard length (SL) in centimeter and total weight (TW) in grams were measured. The class interval was 0.5 cm, the average environmental temperature was 28 ºC and 95% confidence intervals were estimated. The frequency distribution data to match with a normal curve. The estimated values for L? , K y t0 were 22.7 (± 0.14) cm TL, 0.28 (+ 0.01) year-1 and ?0.64 years, respectively, consequently the Yalua is considered a fish with longevity and growth rate medium. The estimated total mortality (Z) was 1.97 (± 0.13) year -1 , the natural mortality (M) 0.84 year ?1 , the mortality by fishing (F) 1.13 year ?1 and the exploitation rate (E = F/Z) was 0.57. The length at first capture (Lc) was 14.4 cm TL and the mean length in the catch was 15.5 cm TL. 42% of the capture was made under the mean length in the catch recommended for the Sinu river basin, the capture and mean length in the catch of Yalua estimated by the INPA has oscillated from previous years, in the dry season of study year were catched very small individuals and consumed for fishermens, in Lorica individuals with similar lengths to the 2001 and 2002 years were commercialized, it is inferred that the Yalua is becoming a replacement species of the commercialized traditionally, that resource is being over fishing, thence, it is inferred that the dynamic population of species has been affected. Therefore, the fisheries ordering should be introduced in the medium term, considering that the Yalua is the fourth species in commercial importance in the Sinu river basin.