Parámetros de crecimiento de Cardisoma guanhumi en el departamento del Magdalena, Colombia

Abstract

In Colombia, the blue land crab Cardisoma guanhumi faces two main threats: extraction and habitat loss. This project aims to show an approximation of the growth parameters of C. guanhumi in protected areas within the Magdalena department. Individuals were captured monthly from May to October 2016 in five localities in the Tayrona National Natural Park (PNNT) and the Salamanca Island Road Park (VIPIS). A total of 816 crabs were collected, each of which was measured, weighed, sexed and released. Both sexes showed a negative allometric length-to-weight ratio. Using the FiSAT II program's ELEFAN I routine, the size frequencies obtained were analyzed in order to determine the growth parameters for 1) the department, considering gender, and 2) the PNNT, where the data from VIPIS wasexcluded. The asymptotic carapace width was higher for males (109.16 mm) than for females (96.74 mm), but the growth coefficient (K) was higher for females (0.19 year-1) than for males (0.15 year-1). Growth performance indexes were similar: 3.252 for males and 3.250 for females. The FISAT II length converted catch curve routine was used to calculate the total (Z), natural (M), and fishing (F) mortalityrates, as 0.41, 0.36, and 0.05 year-1 respectively. The grow coefficient K was higher for the PNNT (0.29 year-1) than for the Magdalena department (0.15 year-1), thus, longevity was lower for the PNNT (tmax= 10.42 years) compared to the department (tmax= 20.06 years). Ingeneral terms, the C. guanhumi population in the study area is longevous, slow growing, with low extraction morality. The data obtained in this work are important in the management of this species, as its slow growth makes it vulnerable to overfishing.