Life history stage duration and natural mortality for the pink shrimp Farfantepenaeus duorarum (Burkenroad, 1939) in the southern Gulf of Mexico, using the gnomonic model for time division

The gnomonic model proposed by Caddy [Aquat. Living Resour. 9 (1996) 197] to estimate life history stage duration and natural mortality values (M) is applied to the pink shrimp Farfantepenaeus duorarum of the southern Gulf of Mexico. Estimates of life history stage duration and M were consistent with other estimates in the literature. Evidence from the literature suggests that M declines with age, which is also reflected by results through the gnomonic model. If the product of natural mortality and duration for gnomonic intervals is close to constant, as assumed by the model, then age specific natural mortality rates estimated in this study may be useful in modeling and managing the fishery for pink shrimp.