Estuarine dependency and life history evolution in temperate sea basses

Abstract

The Asian temperate sea bass, Lateolabrax japonicus has strong taxonomic affinities with the North American Morone saxatilis and European Morone labrax, despite wide geographic separation. L. japonicus and M. labrax populations exhibit varying levels of estuarine dependency (facultative amphidromy), while M. saxatilis shows varying levels of coastal dependency (facultative anadromy). Based upon phylogenetic evidence, it is hypothesized that anadromy in M. saxatilis evolved from a marine-spawning ancestor, contrary to the prevailing view for salmonids: that anadromy evolved from freshwater ancestors. Higher stability of east coast North American estuaries in comparison to European and Asian estuaries may explain the unique pattern of anadromy and freshwater radiation in North American temperate basses.