TY JOUR TI BREAM FECUNDITY (ABRAMIS BRAMA LINNAEUS, 1758) IN THE VOLGA DELTA KW bream KW individual absolute fecundity KW relative fecundity KW sexual maturation JO Vestnik of Astrakhan State Technical University. Series: Fishing industry AU Ivanov, V.. AU Levashina, N.. PY 2018 IS 2018 PB Astrakhan State Technical University