A molecular phylogenetic perspective on the evolutionary history of Alosa spp. (Clupeidae)

Abstract

Clupeidae is one of the world’s most commercially important family of Wshes. Within Clupeidae, the genus Alosa (subfamily Alosinae) has received research attention concerning its ecology and life-history (Bagliniere, 2000 and references therein), as well as conservation issues due to recent declines in many of its species (Waldman, 2003). Despite their importance, little is known about the phylogenetic relationships within Alosa, resulting in systematic and taxonomic uncertainty, which may undermine the establishment of adequate conservation measures. Drawing on the work of Economidis and Sinis (1986) and Whitehead (1985); Bagliniere (2000) listed 16 species native to the northern hemisphere distributed through the western and eastern Atlantic coasts; Mediterranean, Black, and Caspian Seas; and Lake Volvi (Greece). Although most of these species are anadromous, there are two amphidromous, one marine and one strictly freshwater species. However, within some anadromous species there are populations that complete their entire life cycle in freshwater environments. This variation in life-history strategies together with the capacity to colonize new habitats makes species of Alosa interesting models to study speciation and adaptation. In addition, enormous intraspeciWc morphological variability has been described making the application of molecular techniques crucial to understand the phylogenetic relationships between species. Alosa was initially classiWed into three genera: Pomolobus, composed of four North American species (now