Semianadromous Fish

any one of a biological group of fishes occupying an intermediate position between resident and anadromous fishes. Semianadromous fishes feed in brackish waters at the mouths of rivers that empty into seas or in “sea-lakes” (for example, in the Caspian and Aral seas). To reproduce the fishes travel to the lower courses of rivers but usually do not move too far up against the current. They spawn in fresh water. Semianadromous fishes differ from anadromous fishes in that they do not live in water with oceanic salinity and usually do not travel too far out to sea. Semianadromous fishes include several lake whitefish, the roach, and the European bream. Many species are commercially valuable.