Genetic monitoring of the Mexican four-eyed octopus Octopus maya population: New insights and perspectives for the fishery management

Abstract

The Octopus maya fishery is one of the most important among the octopod fisheries in America. Recent studies about the wild population of this species, have contributed to understand that population variations and dynamics are highly influenced by temperature. The distribution area of this species could be divided in two well-differentiated thermal zones: an eastern zone influenced by the upwelling pulses, and a western zone with no upwelling influence. There is evidence suggesting that variations in population parameters could be linked to these thermal zones. However the fishery is still managed as one single unit, and there is no control of the capture limit. In this study we analyzed the multilocus microsatellite genotypes of wild O. maya across its distribution area to find out if the population is structured, and if the structure matches the mentioned thermal zones. Additionally, the heterozygosity was compared between samples from 2010 and 2015 to monitor changes related to the high fishing pressure. Results show that O. maya population is structured in two clusters that match with the different thermal zones in the distribution area. Moreover, significant genic differentiation was detected between these thermal zones. On the other hand, despite the high fishing pressure over this species, there is no significant difference in heterozygosity between 2010 and 2015 samples, and no inbreeding was detected, showing that genetic diversity is still high. We recommend the continuous monitoring of heterozygosity in this species, and a separate fishery management for Campeche (western) and Yucatan (eastern) subpopulations.