Phylogenetic and Biogeographic History of the Snooks (Centropomidae: Carangiformes) Spanning the Closure of the Isthmus of Panama

Aim

Amphiamerican New World fishes provide a unique opportunity to explore the impact of geological processes and the formation of geographic barriers on biological diversification across both spatial and temporal dimensions. We employed phylogenetic and biogeographic methods to assess the impact of the emergence of the Isthmus of Panama on the evolutionary history of snooks.

Location

Eastern tropical Pacific and western Atlantic Oceans.

Methods

Bayesian methods were used for phylogenetic inference and divergence time estimation, incorporating the fossil record of Carangidae, Centropomidae, Istiophoriformes, Latidae and Sphyraenidae to establish a timeline using the methods of stratigraphic intervals for node calibration density specification. Biogeographic models were fitted to test the hypothesis that transisthmian vicariant events are coeval with the Isthmus closure. To estimate ancestral range probability and perform stochastic mapping, we utilised BioGeoBears and the parameters from the best-fitting model. This allowed us to estimate the quantity and kind of biogeographical events.

Results

Our results suggest a sister relationship between Centropomidae and Sphyraenidae with a common ancestor that originated in the Upper Cretaceous (~78.51 Ma). The biogeographic model BAYAreaLIKE + j indicated speciation in sympatry and dispersal (founder effect) as the primary modes of speciation in the genus Centropomus. The dispersion in the family Centropomidae was estimated from the Tropical Eastern Pacific to the tropical western Atlantic since the Oligocene.

Main Conclusions

The alignment of divergence times with ancestral species distributions suggests a possible synchrony between the current distribution in Centropomus species and the processes of the formation of the Isthmus of Panama during the Miocene. However, the evidence of only two transisthmic pair suggests that this event was not determinant in allopatric interbasin speciation. Furthermore, recent diversification events within each basin imply an influence of post-closure environmental conditions on the evolution of this group of fishes.