Acceso en línea sin restricciones

Con el objetivo de determinar la edad y el crecimiento de la sierra Scomberomorus maculatus, en la Bahía de ChetUinal, se efectuaron muestreos de octubre a diciembre de 1989 y de marzo a junio de 1990; con los resultados se aplicaron los métodos indirectos de análisis de frecuencia de tallas y como validación se aplicó la técnica de lectura de otolitos. El método de Shepherd fue el. que mejor representó los pararnétros de crecimiento obtenidos del modelo de Von Bertalanffy, It= 705 (l_e·0.36H+O.36», se identificaron la presencia de organismos de VI clases de edad, siendo los adultos tempranos de la edad II y III, los que soportan esta pesquería, la cual se considera incipiente y se concluye que no se está afectando a los juveniles aún cuando la pesquería se encuentra en desarrollo. Español

To determine age and growth rate of the Spanish mackerel Scomberomorus maculatus, the Bay of Chetumal, Mexico was sampling in October-December 1989 and March-June 1990. Of 780 individuals collected, fork length and weight were measured in 480 (from these, 200 otoliths were extracted). Indirect methods were applied to length-frequency analysis and were validated by comparison with otolith readings with the T-student test applied to the age classes estimated by every method pair. The differences were not statistically significant between Bhattacharya and otolith methods (t=0.007, p<0.05) and between Shepherd´s and otolith methods (t=1.43, p<0.05). However, for estimations calculated between ELEFAN and otolith, the results were different (t=1.93, p<0.05). Shepherd's method fits growth parameters better than the Von Bertalanffy growth curve lt= 705 (1-e-0.36(t+0.36)). These growth parameters were compared with reports from Brazil and Florida and some differences were noticed, but these are attributed to methodological differences. Probably the most important aspect is that those studies were carried out with different populations. The weight-length data set was used to obtain the relationship W=0.000025 L2.83 (r_=0.95, p<0.001), concluding that the growth type of Spanish mackerel is isometric. Based on the statistical test the growth parameters obtained with the Shepherd´s method were used in the subsequent analysis and six age classes were identified. The population is well recruited at the third age, young adults of classes two and three and adults of the fourth age class support the fishery, which is considered incipient. The identified age classes indicated the selectivity of gillnet to fishes between 400 mm and 633 mm of LF; the most important age class identified was age three because this class is the recruitment age and contributes with the highest percentage of the fishery; individuals with 640 mm of LF or more, were not captured, therefore the Chetumal Bay population of the oldest adults (VIII age classes or more) is not affected by gillnet or is not present in the Bay. Juveniles are not affected even though the fishery is still developing. Inglés