Richness of the exploited species in the octopus fisheries of the Gulf of Mexico

Abstract

A wide variety of octopus species are commercially harvested in artisanal fisheries, but official landing data are still limited. This study thoroughly examined landings from 10 ports across four sampling operations to evaluate the species richness of octopuses marketed in the southern Gulf of Mexico (GoM). We selected a total of 61 specimens for morphological and meristic analysis and conducted COI genetic identification on 11 specimens that exhibited ambiguous morphological traits. We identified two genera and seven octopus species by integrating morphometric and genetic methods. The Chao richness index suggests that at least nine species can be captured in southern GoM fisheries. Our combination of field identifications and literature reviews revealed four target species: Octopus maya, O. americanus, O. insularis, and Callistoctopus furvus. Additionally, we found two incidental species, Amphioctopus burryi and O. hummelincki, and three discarded species: O. briareus, Macrotritopus defilippi, and O. joubini. These findings highlight the multi-species composition of the octopus fishery in the region, revealing greater diversity than is currently recognised in management plans. The results underscore the need to revise management strategies to account for this biodiversity, thereby ensuring the sustainable exploitation of these valuable resources.