Density and population size of the ghost crab (ocypode gaudichaudii) on four beaches of continental Ecuador

Abstract

Population density and population size are related to the conditions and effects of the environment on a population. In this sense, the objective of this study was to determine the density and population size of the species Ocypode gaudichaudii in four beaches of the province of Manabí, Ecuador; which were Punta Bikini, San Jacinto, Los Ranchos and La Boca. Population density was estimated using the distance method with linear transects. On the other hand, the data was processed with the specialized Distance 7.3 software and different detection functions and definitions were used. From this, a total of 1600 burrows were obtained in the study area of the four beaches. The estimated population density was 0.42 ind/m2 (I. C.: 0.36-0.48 ind/m2), with 7.29% CV; while the population size, 5911 individuals (I. C.: 5098-6854 individuals). Among the main results, it was identified that the density and population size of O. gaudichaudii differed between test sites; These differences were related to the anthropogenic impact such as the mobilization of vehicles and boat dragging (i. e., Los Ranchos) and the estuarine influence (i. e., San Jacinto). It is concluded that it is necessary to determine the influence of the physical environment and environmental and chemical of variables on the density and population size of O. gaudichaudii.