Alosa to detect ultrasound (at frequencies above 20 kHz, which is the limit of human hearing). This was first discovered by fisheries biologists studying a type of shad known as blueback herring, and was later verified in laboratory studies of hearing in American shad. This ability is thought to help them avoid dolphins that find prey using echolocation. "Alosa" species are generally pelagic. They are mostly anadromous or semianadromous with the exception of strictly freshwater landlocked species. "Alosa" species are generally migratory and schooling fish. Males usually mature about a year before females; they spawn in the late spring to summer.
Types of fish in Uganda 1960. Although Lates was introduced into Lake Victoria in the early 1960s it took more than 10 years to get fully established in the new ecosystem. They weigh up to 80 kilograms. It is locally known as "Ngege" ("Oreochromis esculentus"). It is among the oldest types of fish in Uganda. Nile tilapia (Oreochromis niloticus) are native species to Lake Albert, the River Nile below Murchison Falls, Lake Turkana, the Chad basin and rivers of West Africa (Lowe-McConnell, 1988). Catfish is locally known as "Semutundu" and Bagrus Catfish, Bagrus docmak (scientific name). It is grey-black above, creamy white below. It lives