ABSTRACT

The spawning areas of the American eel, Anguilla rostrata Le Sueur (1817), and the European eel, A. anguilla Linnaeus (1758) are known to be neighboring in the Sargasso Sea (Schmidt 1922, 1925) (Fig. 1). American eel leptocephali drift coastward through the Gulf Stream from the Sargasso Sea, whereas European eels are further transported by the North Atlantic Current across the Atlantic Ocean (Schmidt 1922, 1925; Power and McCleave 1983; Boëtius 1985; Kleckner and McCleave 1985) (Fig. 1). The eels grow in the inland freshwaters of eastern North America and Western Europe (Schmidt 1925; Tesch 1977; Kleckner et al. 1983; Kleckner and McCleave 1988) and are distinct, genetically different species (Camparini and Rodinó 1980; Avise et al. 1986), rather than environmentally determined, eco-phenotypic species (Tucker 1959).