Attributes / relations provided by
♦ ¹Lappalainen, A., M. Rask, H. Koponen & S. Vesala, 2001. Relative abundance, diet and growth of perch (Perca fluviatilis) and roach (Rutilus rutilus) at Tvärminne, northern Baltic Sea, in 1975 and 1997: responses to eutrophication? Boreal Env. Res. 6: 107–118
♦ ²Predation of the shelduck Tadorna tadorna on the mud snail Hydrobia ulvae, N. R. Anders, T. Churchyard, J. G. Hiddink, Aquat Ecol 2009, vol. 43, no. 4, pp. 1193-1199