The Free Online Aquaculture Dictionary

 Nile Tilapia (Oreochromis niloticus)

Thanks to Mike Sipe for pictures
Oreochromis niloticus are a species native to Africa and as one of the tilapia species with the Northern most range, it is tolerant of lower temperatures than many other species.  The O.NIloticus is one of the major species used in tilapia production round the world and is used in many hybrid crosses.