Golden Freshwater Clam

Oreochromis aureus

Blue tilapia (Oreochromis aureus) is a cold tolerant species that can live in both freshwater and brackish water. Thanks to these favorable characteristics it has become a popular species among fish farmers world wide and especially in regions where cold tolerance is of imperative importance. Oreochromis aureus is not only grown for the food market; it is also frequently sold as bait.

Oreochromis aureus has been used to develop several tilapia variants especially suited for aquacultures, such as the ND21 tilapia and the ND41 tilapia.

The ND 21 hybrid is the result of crossing a male Blue tilapia of the ND-1 Tilapia family line with a female Nile tilapia (Oreochromis niloticus) of the ND-2 Tilapia family line. One of the main advantages of this crossing is that virtually all offspring will be males. This makes it easy for fish farmers to avoid uncontrolled breeding in their growing units. Uncontrolled breeding can lead to crowding and stunting and will force the adult fish to compete with fry and fingerlings for food.

The ND 41 tilapia is the result of crossing a male Blue tilapia of the ND-1 Tilapia family line with a female Blue tilapia of the ND-4 Tilapia family line.  ND-1 and ND-4 are both cold tolerant and can spawn in 20 °C (68 °F) water. The ND 41 is also very cold tolerant and will actually grow faster than the famous Nile tilapia (Oreochromis niloticus) in the temperature interval 22-25 °C (72-77 °F).

The wild Oreochromis aureus inhabits many different bodies of water, including ponds and impoundments, and will therefore normally adapt well to a life in a pond, cage or tank. They are considered freshwater fish, but they do occur in brackish environments in the wild and have even been found living in a few marine locations.

Just like many other tilapia species the Blue tilapia can turn into a problematic invasive species and fish farmers must therefore be cautious.