Industrial pump specifically developed for the transport, transfer or harvesting of live fish. Built in robust, corrosion-resistant materials ensuring a long life time with minimum maintenance, including rotor and shaft in AISI316L stainless steel. Automatic programming, electric or gasoline-powered motor, water level control and electrical protection for aquaculture environs. Based on the pressure-vacuum principle, allowing for the transfer of live fish with minimum damage to scales and tegument. Easy to operate, the state-of-the-art 4 valve design facilitates cyclical operations even under very adverse conditions. Fits automatic graders and counters (Technical Sheets nº 510 and 511), making the transfer, grading and counting of live fish possible within a single operation.