DEMOGRAPHY OF THE BONNETHEAD SHARK, SPHYRNA-TIBURO (LINNAEUS, 1758), IN THE SOUTHEASTERN GULF-OF-MEXICO

The bonnethead shark, Sphyrna tiburo, is one of the most abundant spec ies in catches from the Gulf of Mexico, particularly from Campeche. It is mainly caught with gill nets and it is available throughout the ye ar. A demographic analysis was carried out, incorporating the best ava ilable information about its life history, such as age at first maturi ty, fecundity, longevity, sex ratio (1:1) and age-specific natural mor tality. The age and growth data used come from northern individuals of the Gulf of Mexico. The first run was done to obtain the demographic parameters under natural conditions. Other simulations varying age at first capture and incorporating fishing mortality were made to estimat e the rate of change of the net reproductive rate (R-o), generation ti me, intrinsic rate of increase and doubling time. Using an age-structu red dynamic model, R-o, was projected until the year 2010. The results of the simulations showed that S, tiburo has a higher reproductive po tential than other sharks. This analysis will allow us to establish th e management strategies for the fishery.