Breeding seasons and sizes at first maturity for nine species of fish in the Avon‐Heathcote Estuary, Christchurch, New Zealand, were: sand flounder,Rhombosolea plebeia, mid‐winter to spring at 200 mm+; yellow‐bellied flounder,Rhombosolea leporina, winter and spring at 260 mm+; common sole,Peltorhamphus novaeieelandiae, did not breed in the estuary but reached first maturity at 220 mm +; yellow‐eyed mullet,Aldrichetta forsteri, spawned twice a year, winter and summer, at 220 mm +; kahawai,Arripis trutta, bred outside the estuary at 520–540 mm +; spotty,Pseudolabrus celidotus, spring to autumn at 200 mm for males and 160 mm for females; cockabully,Tripterygion nigripenne, spring and early summer at 52–57 mm +; common bully,Gobiomorphus basalis, spring and early summer at 45–50 mm+; and globefish,Speroides richei, spring to autumn at 147 mm + for males and 120 mm + for females. The successive stages in gonad development are described for these species.