Multi-Model Allometric Analysis in the Slipper Lobster Evibacus princeps from the Gulf of California

The slipper lobster Evibacus princeps occurs as part of the bycatch in industrial shrimp fisheries of the Mexican Pacific. Although biological information on this species is limited, the Food and Agriculture Organization (FAO) currently classifies it as a subsistence resource with potential for exploitation. Accordingly, this study aimed to provide baseline information on selected biological aspects of E. princeps associated with industrial shrimp fishing in the Mexican Pacific. A total of 546 individuals were collected during the 2021–2022 fishing season. Female carapace length (CL) ranged from 23.96 to 139.23 mm, whereas males ranged from 16.19 to 124.75 mm CL. The size-frequency distribution of both sexes exhibited two distinct modes, suggesting that the study area may function as a permanent habitat for the species. Morphometric relationships among total length, carapace length, carapace width, and length of the third pair of pereiopods in females and the fifth pair in males were analyzed to evaluate allometric growth. Females showed positive allometric growth, growing proportionally wider than longer, from 20 to 85 mm CL. Beyond this size, they exhibited negative allometric growth. Males displayed positive allometric growth from 16 to 41 mm CL, after which negative allometric growth occurred. These findings provide baseline population information that may support future ecological, conservation, and fisheries-related studies of the species.