Dispersal modeling of octopoda paralarvae in the Gulf of Mexico

Authors: Mariana L. Santana-Cisneros, Pedro-Luis Ardisson, Ángel F. González, Ismael Mariño-Tapia, Miguel Cahuich-López, Luis Enrique Ángeles-González, Uriel Ordoñez-López, Iván Velázquez-Abunader

https://doi.org/10.1111/fog.12555

Abstract
The dynamics and population structure of octopus species in the Gulf of Mexico (GoM) can be studied by analyzing dispersal paralarvae mechanisms. Accordingly, this study focused on understanding octopus paralarval dispersal using numerical modeling. A Lagrangian approach was implemented using the transport model ICHTHYOP and surface currents from a GoM simulation of the HYbrid Coordinate Ocean Model (HYCOM). We modeled the dispersal of four octopus species from the GoM (Octopus “vulgaris,” Octopus insularis, Macrotritopus defilippi, and Amphioctopus burryi), considering two regions as the source of larvae in the southern GoM, namely the Yucatan shelf and the Veracruz coastal waters. Additionally, an environmental suitability analysis was incorporated using the maximum entropy (MaxEnt) model to establish potential settlement areas under the influence of the water masses’ thermal conditions. The simulation results supported the hypothesis that the abundances recorded in the GoM were influenced by the fertility (egg-laying) of each species, surface water circulation (the Loop Current, eddies, and wind), and sea surface temperature. Greater dispersal was obtained throughout the GoM for Yucatan species O. “vulgaris”, registering the highest settlement rates. In contrast, in Veracruz, O. insularis dispersed and settled only in the western portion of the GoM. The relevance of the ecological descriptors proposed to influence the dispersal and abundance of octopods throughout the GoM’s coastal waters are discussed.

Keywords: fertility, Gulf of Mexico, Lagrangian model, larval transport, MaxEnt, octopus, settlement