Comparing early life history strategies of Pomatomus saltatrix: A global approach

Pomatomus saltatrix (Pisces: Pomatomidae) is a highly migratory, continental-shelf species with a worldwide subtropical distribution including the eastern coast of North America, the Gulf of Mexico, Mediterranean Sea, Black Sea, north-western Africa, the eastern coast of South America, the south-eastern coast of South Africa, and the south-eastern and south-western coasts of Australia. This paper summarizes available life history information from the different regions where P. saltatrix occurs, with a focus on the early life history. The basic physical oceanography of these regions is also reviewed to elucidate patterns in larval transport. Comparison of these populations suggests that there are commonalties: adults migrate to spawning grounds; eggs and larvae are typically advected along-shore to juvenile nursery habitats; juveniles recruit to inshore habitats at a similar size, and there they grow rapidly and are mainly piscivorous, feeding primarily on atherinids and engraulids. There are also a number of life history traits that are quite variable among populations: the number of annual reproductive peaks, the number of juvenile cohorts, adult growth patterns and reproductive parameters. Comparison of these life history patterns leads to several non-exclusive hypotheses as to the adaptive significance of variations in life history traits. The goal is to identify areas where more research is needed to assess the degree to which populations of a global species are adapted to their local environment.