by Henrylito D. Tacio
“PUT out into deep water, and let down the nets for a catch,” Jesus told Simon Peter. Not knowing who Jesus was, the fisherman objected, “We’ve worked hard all night and haven’t caught anything. But because you say so, I will let down the nets.”
When Peter and his brother Andrew had done so, they caught such a large number of fish that their nets began to break. So, they signaled their partners in the other boat to come and help them, and they came and filled both boats so full that they began to sink.
The rest is now a history. But have you ever wondered what kind of fish they caught in the Sea of Galilee centuries ago? If you answer tilapia, then you got it right!
Today, tilapia is now widely distributed around the world. It has become the mainstay of many small-scale aquaculture projects of poor fish farmers in the developing world. “The fish is cultured in more than 70 countries,” says Dr. Rafael D. Guerrero III, the executive director of the Philippine Council for Aquatic and Marine Research and Development (PCAMRD).
Fishery experts have dubbed tilapia as “aquatic chicken” because it possesses many positive attributes that suit the fish for a varied range of aquaculture systems. For one, tilapia tolerates a wide range of environmental conditions and is highly resistant to diseases and parasitic infections.
Other good traits of tilapia include excellent growth rates on a low-protein diet, ready breeding in captivity and ease of handling; and, more importantly, wide acceptance as food fish.
“Tilapia has become a very important fish in the world, especially in Asia and Africa,” says Dr. Guerrero, who holds a doctorate degree in fisheries management from Auburn University in the United States. “Where you have a problem of protein deficiency, where there is hunger and malnutrition, people depend on rice and cultured fish like tilapia.”
Next to milkfish (more popularly known as bangus), tilapias are among the widely cultured species in the Philippines. The culture of tilapia in freshwater ponds and cages has been a commercial success. Currently, there are an estimated 15,000 hectares of freshwater ponds and 500 hectares of cages in lakes in lakes and reservoirs producing over 50,000 metric tons of tilapia.
There are four species raised in the country: Oreochromis niloticus, O. mossambicus, O. aureus, and Tilapia zillii. “Tilapia culture in the Philippines started in the 1950s with the introduction of Mozambique tilapia, a small, black species that was not accepted in the market,” Dr. Guerrero recalls. “It was touted as a miracle fish. But there were difficult problems in its management, including overpopulation.”
The fish is a prolific breeder that multiplies rapidly. Crowded surroundings stunt its growth. “People criticized the small size of the fish,” he says, “and it was sold at very low prices.”
It was not until the Nile tilapia was introduced in the country that Filipinos started to like the fish. “The Nile tilapia became popular because of its rapid growth, large size and high yield potential,” notes a PCAMRD briefing paper. “Like other tilapias, this species is resistant to parasites and diseases, resistant to overcrowding and has the ability to survive low oxygen levels. They also grow in both natural and artificial fish foods, and utilize manure well. They are excellent table food fish with white firm flesh and no intramuscular bones.”
As a result of tilapia’s popularity among Filipinos, the Philippines is now ranked fourth among the top ten largest tilapia producers in the world – after China, Egypt and Thailand. Other top producing countries, according to the UN Food and Agriculture Organization (FAO), are Indonesia, Uganda, Mexico, Tanzania, Kenya, and Sri Lanka.
Tilapia production grew by 5 percent during the last 14 years, noted the industry strategic plan for tilapia. This served as a major determinant in the gross supply of tilapia in the country. Tilapia surplus stood around 2,000 to 5,000 metric tons during the same period. At 2020, the surplus is expected to reach around 10,000 metric tons.
The popularity of tilapia has made it as one of the most in-demand fish. “With its wider acceptability in the Filipino table and the growing population, the total tilapia supply needs to be increased,” Dr. Guerrero points out.
From 1990 to 2004, tilapia per consumption has steadily increased by an average of 5 percent. From as low as 1.54 kilograms per capita in 1990, consumption increased to 2.03 kilograms per capita in 2004. “Using this information as a background for projection,” said the strategic plan paper, “consumption is expected to increase further to 2.35 kilograms per capita in 2010, 2.65 kilograms in 2015, and 3.0 kilograms in 2020.”
Prices of tilapia vary according to size, degree of freshness and supply and demand situation. Tilapia commands higher price when sold during holidays and when the catch of marine fish is low especially during bad weather condition. However, the Bureau of Agricultural Statistics noted that the retail price of tilapia is steadily increasing: from P34.22 per kilogram in 1990 to P67.33 per kilogram in 2004. The price is definitely higher today.
Here’s another good news: Tilapia products – fresh and frozen fillets, whole and gutted fish – have become important commodities in the international seafood trade. However, the Philippines “cannot supply the international market with frozen whole fish” since our price is much higher than those coming from Thailand and Taiwan.
The popularity of tilapia in the Philippines is credited to Dr. Guerrero. In 1987, he received the prestigious IBM Science and Technology Award for his contribution in making the tilapia the second most important cultured fish in the country (after bangus). He was also cited for developing simple, low-cost tilapia hatchery techniques. One of his notable achievements is the development of SRT-99, a feed that reverses the sex of young fish and makes tilapia males grow up to 800 grams, or six times bigger than unsexed tilapias.
Actually, SRT-99 is a feed for tilapia fry that contains a synthetic male hormone that induces sex reversal – the conversion of genetic females into functional males. “When applied properly, SRT-99 can produce 95 to 99 percent male tilapia fry in 21 days,” Dr. Guerrero explains.
A manual published by Aquatic Biosystems – a firm that Dr. Guerrero co-founded with his wife, Luzviminda and the exclusive distributor of SRT-99 – gives details on the use of the feed:
“Collect fry in the breeding ponds or tanks when they are seven to 10 days of age with a total length of nine to 11 millimeters. Stock the fry in the treatment units at the appropriate density (250 to 1,000 square meters) and feed them with SRT-99 immediately.
“For the first week, feed SRT-99 at the rate of 20 percent of fry body weight (0.01 gram) daily. For every thousand fry, use two grams of SRT-99 per day in four feedings at regular intervals from 8 a.m. to 4 p.m.
“On the second week, feed at the rate of 15 percent of fry body weight (0.05 gram) daily. One thousand fry are fed 7.5 grams of SRT-99 per day.
“On the third week, reduce feeding to 12 percent of fry body weight (0.1 gram). A thousand fry will require 12 grams of SRT-99 per day.
“After the 21-day treatment, transfer the fingerlings to regular nursery or stock them in culture ponds free of predators and unwanted fishes.”
Tilapias are the most important group of fishes of the large and diverse ‘Cichlidae’ fish family, which comprise about 700 species. Cichlids are mainly found in Africa and South America.
In 1840, the British naturalist A. Smith gave the fish its name. The word tilapia is derived from the African bushmen’s term for fish. The natives’ word for the fish began with a clicking sound that Smith interpreted as til. — ###