Blue tilapia

The blue tilapia (Oreochromis aureus) is a species of tilapia, a fish in the family Cichlidae. Native to Northern and Western Africa, and the Middle East, through introductions it is now also established elsewhere, including parts of the United States, where it has been declared an invasive species and has caused significant environmental damage.  It is known as the blue kurper in South Africa.

Whole tilapia fish can be processed into skinless, boneless fillets: the yield is from 30 to 37%, depending on fillet size and final trim. In some of the commercial strains, the yield has been reported up to 47% at harvest weight.

Tilapia have very low levels of mercury, as they are fast-growing, lean, and short-lived, with a primarily vegetarian diet, so do not accumulate mercury found in prey. Tilapia are low in saturated fat, calories, carbohydrates, and sodium, and are a good protein source. They also contain the micronutrients phosphorus, niacin, selenium, vitamin B₁₂, and potassium.

Some research has found that tilapia may be a less nutritious fish than generally believed. The Wake Forest University School of Medicine released a report in 2008 showing that the fish’s omega-3 fatty acid content is often far lower than that of other commonly eaten fish species. The same study also showed that their omega-6 fatty acid levels were unusually high. Multiple studies have evaluated the effects of adding flaxseed derivatives (a vegetable source of omega-3 fatty acids) to the feed of farmed tilapia. These studies have found both the more common omega-3 fatty acid found in the flax, ALA and the two types almost unique to animal sources (DHA and EPA), increased in the fish fed this diet. Guided by these findings, tilapia farming techniques could be adjusted to address the nutritional criticisms directed at the fish, while retaining its advantage as an omnivore capable of feeding on economically and environmentally inexpensive vegetable protein. Adequate diets for salmon and other carnivorous fish can alternatively be formulated from protein sources such as soybean, although soy-based diets with soy oil may also change in the balance between omega-6 and omega-3 fatty acids.

In Taiwan, tilapiine cichlids are also known as the “South Pacific crucian carp“, and since their introduction, have spread across aquatic environments all over the island. Introduced in 1946, tilapiine cichlids made a considerable economic contribution, not only by providing the Taiwanese people with food, but also by allowing the island’s fish farmers to break into key markets, such as Japan and the United States. Indeed, tilapiine cichlids have become an important farmed fish in Taiwan for both export and domestic consumption.

The Chinese name for the fish in Taiwan is wu-kuo (吳郭), and was created from the surnames of Wu Chen-hui (吳振輝) and Kuo Chi-chang (郭啟彰), who introduced the fish into Taiwan from Singapore. The Taiwan tilapia is a hybrid of Oreochromis mossambicus and O. niloticus niloticus.