Oreochromis aureus is a popular species in tilapia farms all over the world. It is especially appreciated in colder areas where the cold tolerance of this species makes it possible to successfully farm tilapia in areas where it might not be possible with other species. Oreochromis aureus tolerates both fresh and brackish water. It is farmed and sold as a bait fish in addition to being sold as a food fish. The common English name for Oreochromis aureus is Blue tilapia.
Blue tilapia can be found in a multitude of different habitats in the wild. They can be found in most types of bodies of water and this means that they adapt well to most types of tilapia farming. They do well in tank, pond and cage farming. They can be found in waters ranging from pure freshwater to brackish and eve marine locations. Even though there are wild populations of tilapia living in marine locations, this species is only recommended for fresh and brackish water when kept in fish farms.
Since it is such a flexible fish, the Blue tilapia can today be found as an invasive species in many parts of the world and tilapia farmers need to take care not to introduce it into even more waters where it does not belong.
The Blue tilapia has been used to develop a number of different hybrid tilapia strains designed for tilapia farming. Examples of such hybrid strains are ND21 Tilapia and ND41 tilapia.
The ND21 Tilapia hybrid was created by crossing a male Blue tilapia (of the ND1 strain) with a female Nile tilapia (Oreochromis niloticus of the ND 2 strain). The resulting ND21 Tilapia has several advantages. One of the most important improvements is that all the fish are male which makes this strain perfect for mono sex cultivation. Mono sex cultivation is a way of avoiding unwanted spawning, since spawning is known to reduce the growth rate of the tilapia by increasing fish density in the farm, not to mention that the fish waste energy on spawning they could have used to grow even faster.
ND41 Hybrid tilapia is the result crossing a male blue tilapia (ND1) with a female blue tilapia (ND4). Both ND1 and ND4 are cold tolerant and the resulting fish is very cold tolerant and can outgrow Nile tilapias (Oreochromis niloticus) in the temperature interval 22-25 °C (72-77 °F). The ND41 Hybrid tilapia can even spawn in water that is 20 °C (68 °F), making them much more cold hardy than most other tilapia strains.