Density, structure, growth, and mortality of the population of Ocypode gaudichaudii H. Milne Edwards & Lucas, 1843 (Brachyura, Ocypodidae) in Salaverry, Peru

The northern coast of Peru includes a series of dissipative desert beaches with varying levels of human impact. One endemic species to these beaches is Ocypode gaudichaudii, which has been shown to be an indicator of ecosystem disturbance. We measured population density, sex ratio, and cephalothorax length of O. gaudichaudii on three beaches near Salaverry between September 2021 and February 2022. The average population density was 0.15 burrows/m2. There was a higher proportion of males (56%); and average cephalothorax length was 28.8 ± 5.6 mm. Population, length, and sex variations during the study may be explained by behaviour of O. gaudichaudii and by temperature-dependent breeding. We also calculated the Von Bertalanffy growth parameters (, , ) and estimated the instantaneous mortality rate to be 0.84/year. These data indicate a high level of disturbance in the ecosystem, with few specimens approaching .