The North American bivalve mollusc Ensis directus (Conrad, 1843) (Bivalvia, Pharidae) is native to the Northwest Atlantic coasts from southern Labrador to northern Florida (Bousfield, 1960; Theroux and Wigley, 1983; Swennen et al., 1985; Abbott and Morris, 2001; Turgeon et al., 2009; Vierna et al., 2013). This species has been introduced outside its native range, with the first confirmed record from the German Bight in 1979 (Cosel et al., 1982). Thereafter, a subsequent secondary range expansion took place, and the species is presently known to occur from Spain to Norway, including the UK (e.g. ühlenhardt - Siegel et al., 1983; Essink, 1985, 1986; Kerckhof and Dumoulin; 1987, Luczak et al., 1993; Rasmussen, 1996; Brattegard and Holthe, 1997; Eno et al.,... |