Tilapia- An Abundant Resource of the Philippines
Description and Rationale
Tilapia is a popular native fish among Filipinos that became the third most important fish in aquaculture in 2002. Nevertheless it is known to be very troublesome as it eats plants, digs up the seafloor and fights with other fish. It is a very vigorous fish that can survive in both fresh water and salt water and breed in large numbers. In the Philippines, these fishes can be found almost anywhere, and is a popular delicacy among poor people.
How can tilapia financially aid poor Filipinos who live on coastal regions? How long will it take for tilapias to grow large enough to be cooked or to be sold? Is the cost for breeding tilapia affordable for Filipinos? Will breeding tilapia deplete any one particular resource in the area? When and how often do the fishes mate? Are there any other uses of the fish other than food and if other uses are found, what would be the best way(s) to communicate the findings to the people and barangays on the coastal regions?
What benefits can there be by breeding tilapias? Some believe that much of the destruction of coral reefs is done by tilapias. As written above, Australia already regarded tilapia as pests, because of their violent nature; however they were particularly hard to eradicate. If people gain better knowledge of breeding tilapia and try controlling some of the biological aspects, they could benefit on food and money, and maintain various marine resources that could be destroyed by tilapias.
The primary purpose of this project is to understand the biology and its influence in economy of tilapia particularly in Masinag Wet and Dry Market (MWDM) and to communicate this information to poor Filipinos. This will be done through research on various medias (especially literature) and firsthand observations. Multiple interviews with Filipino fishers and market owners in MWDM will be part of this, too. These findings will help guide the experimental phase, where key variables of the availability of tilapia in the fish market will be further explored.
It is hoped that Filipinos that live along coastal regions improve their quality of life by understanding the biology of tilapia and gaining economical advantages over it.
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Biology
Common Names and Synonyms
The well-known fish, tilapia has three different scientific names named by Boulenger in 1896. The three names are Chromis jallae, Haplochromis jallae, and Tilapia jallae, but it is universally recognized by Tilapia jallae. The fish is known for its dark specks on its back and its heavily spined dorsal fin. Surprisingly, this vigorous fish is also known as “St. Peter’s fish,” because, according to the tale, this fish carried the sheckel coin in its mouth according to Matthew 17: 27 in the Bible. This fish is recognized as Tilapia in Tagalog, a native language of the Filipinos.
Classification
Kingdom: Animalia (Animal)
Phylum: Chordata (Vertebrate)
Subphylum: Vertebrata
Superclass: Osteichthyes
Class: Actinopterygii (Ray-finned fish)
Subclass: Neopterygii
Infraclass: Teleostei
Superorder: Acanthopterygii
Order: Perciformes (perch-like fishes)
Suborder: Labroidei
Family: Cichlidae (wrasse-like fish)
Subfamily: Pseudocrenilabrinae
Genus: Tilapia (tilapia is from Bechuana (Botswana), African native word thiape = fish)
Species: T. jallae
There are 183 subspecies, more or less, in this genus and is found throughout the tropical zones near the equator. Over the last 30 years, the scientific names of tilapia species have been changed numerous times, thus creating confusion in taxonomy nowadays. For instance, Tilapia nilotica was once the scientific name of Nile tilapia, but it was revised to Sarotherodon niloticus, and now as Oreochromis niloticus.
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Morphology and Physical Description
An average harvest-sized tilapia weights around 600 to 800g and is less than a foot long. Some marine enthusiasts say they can grow up to 80cm long. The fish has 1 long dorsal spine, more than 20 dorsal soft ray fins, 1 anal fin, 2 pectoral and 2 pelvic fin, and lastly, 1 caudal fin. The caudal and anal fin has rounded corners and extends vertically in a shape of a fan. When closely observed, all its fins are composed of spines.
Like every other fishes of the Cichlid family, tilapias have an interrupted lateral line across its body. This particular feature differs among species, but all have a pattern that crosses the lateral line (a line along the fish’s side that enables the fish to sense water currents). For Tilapia jallae, dark vertical stripes run throughout its body and diminish as it reaches the bottom. These vertical bars are distinctly visible when the fish is young, but fades as the fish ages.
The internal structure does not vary much compared to other bony fishes. For adults, the spines that stretch outwards from the vertebrae are about 3 to 5cm. The bones are hollow, thin, and fragile compared to other vertebrates, which makes the fish light and allows better control of buoyancy. Additionally, Tilapias have tiny combs in their gills that enable them to filter algae from the water. By doing this, they obtain nutrient just by pumping water. Other unique features include a chamber in the mouth called the buccal cavity. This is used by female tilapias after mating to secure the eggs from predators. They carry the eggs until they hatch, and when it does, the chamber is used for the fry to take refuge from its predators.
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Getting Food
Most marine enthusiasts know that tilapias are omnivorous, but tilapias are also capable of surviving on a plant-based diet. Tilapias enjoy protein-rich duckweed and have the ability to filter algae from the water through its gills. In addition, tilapia ingests plankton, invertebrates in the benthic zone, small fishes, and decomposing organic matter, too. It grows fine feeding on plants, but most fish farmers use trash fish (commercial fish used to feed other fishes) combined with weeds to feed tilapia. Usually, meals containing high-protein is reserved for the fry while adults receive less protein-based meal. In most cases, Tilapias receive ground fish, but adults are capable of consuming live small fishes.
Reproduction
A male Tilapia jallae excavates a nest in water generally shallower than 3 feet and mates with several females through external fertilization. The eggs are laid in the nest by the females and then fertilized by the male. Next, the female stores and incubates the eggs in a chamber in her mouth called the buccal cavity until they hatch within the next three to five days. Even after the eggs hatch and are ready to obtain food by itself, the female protects the offspring in her mouth for several days. Tilapias spawn 3 or more times each year and the total amount of eggs produced ranges between 1,500 to 4300 each year.
Environmental Factors
The Nile tilapia, a very similar species to tilapia jallae, is the least tolerant species to salt water. The best water temperature for tilapia is between 85 to 88 degrees Fahrenheit and growth at this temperature is typically three times greater than at 72 degrees Farenheit. The survivability of Tilapia regarding pH ranges from 5 to 10, but does best within the pH range of 6 to 9. Also, tilapias are more tolerant to nitrite (a highly toxic element to fishes) than most other cultural fishes.
In contrast to its superb tolerance and resistance to diseases compared to other cultural fishes, tilapias also have a weakness. Tilapia is a host to numerous external parasitic protozoans such as Trichodina, Epistylis, and Ichthyopthirius multifiliis. These organisms target the fish’s fry and cause considerable damage to them. Recently, a bacterial infection called the Steptococcus inae caused severe damage to the population. Tilapias are also vulnerable to whirling disease, columnaris, Lyphocystis, and other diseases but these problems occur mostly in water temperatures below 68 degrees Fahrenheit.
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Origin and Distribution
Tilapia is believed to have originated from the Nile River since it has been raised for centuries in Egypt more than 3,000 years ago. This fish is a Cichlid distributed in Central and South America, Texas, West Indies, Africa, Madagascar, Syria, Israel, Iran, Sri Lanka, and coastal southern India. Today, this fish is bred in many Asian countries, the Middle East, and America where the climate is tropical. Tilapia is a tolerant fish found throughout the world with water temperature roughly between 62 to 115 degrees Fahrenheit.
Importance to People
Recently, tilapia became the second most widely farmed freshwater fish in the world next to carps. The worldwide harvest of tilapia now surpass 800,000 metric tons. In America, consumption of tilapia has reached roughly 145 million lbs. in the year 2000, and the rate of consumption has been growing at over 35% each year since 8 years ago. Cagayan Valley, the tilapia capital of the Philippines, produced 14,000 metric tons of tilapia in the year 2007.
Tilapia is typically bred for food. One of the fish farming strategies can be early harvest of Tilapias to reduce the amount of food it eats. Fishes are bred separately depending on their physical maturity, as fry are given more fish meals than the adults. Tilapia is a popular delicacy in the United States and the Philippines, so various cooking methods have been developed; however, many Filipinos are unable to afford the food due to poverty. The prize of tilapias range from 60P to 90P per kilo depending on the size. In some occasions, tilapia is bred to control sea weeds growing that disturb other organisms’ growth.
Survivability and Endangered Status
Because of its incredible tolerance to its environment regarding temperature, salinity, acidity, and resistance against diseases, tilapia is far from being endangered. Its reproduction rate adds to the survivability as one male mate with several females. In fact, countries such as Australia consider it as pests as tilapia’s aggressive nature attacks other fishes in the area. Since it eats a wide variety of food and due to its vast population, it has a tendency to endanger other species by depleting food sources of other organisms. Despite the risk, the Philippines, particularly Luzon, doubled their fish production, since the eruption of Mt. Pinatubo in 1991 and built three more fish farm hatcheries for further development.
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Potential Solutions
What is the most efficient way to use tilapia to financially support poor Filipinos? Tilapias are spread nationwide in the Philippines and many breed it for food as well as for financial support. Yet, this does not benefit the starving families, because of the expensive cost to begin with (fish farm). Knowledge about this valuable resource is unknown to many squatters as they are not educated. This can be changed if Filipinos gain simple knowledge of Tilapia and possible environmental methods that save money. Fortunately, there are several affordable methods of using tilapia environmentally and efficiently to raise money. Three possibilities are listed below that include the advantages and the disadvantages of each.
Possibility 1: Creating Your own Fish Pond (Artificial Pond)
It is a well known fact that tilapias are vigorous fishes that can adapt to harsh environments where other fishes cannot. Nothing can be more helpful than to breed, eat, and sell the remaining for additional money.
Advantages:
1. Tilapia is a popular delicacy among most Filipinos. The meat is soft and with not much bones present which makes it easier to eat.
2. Tilapia is available anytime in the Philippines, but is most sold between September to January (rainy season) according to Rotchie Viernes, an employee of the fish market in Sta. Lucia East Grand Mall.
3. The meat can act as a protein-booster for growing children that require plenty of minerals for brain development.
4. Fishes can be sold for profit and the money can be reinvested or used to provide other necessities. This could protect young, poor beggars on roadways from life-threatening accidents and possibly, educate them for a brighter future.
5. Fortunately, artificial ponds can be easily and cheaply built with hollow blocks and cement. Each hollow blocks cost 0.75Php and a bag of cement cost 190Php, certainly an affordable prize even for poor Filipinos. Water pipes can be connected to supply and drain water. Since the water is stagnant, there is a tendency for pests like mosquitoes to breed in. I assume that tilapias will feed on the pests, but it is not a bad idea to install an automated air pump (available in pet stores) to eliminate the pests in the pond. (The floor will be cemented and the sides will be heightened with hollow blocks.) With these and little labor combined, an artificial pond can be easily made.
Disadvantages:
1. Artificial ponds are affordable, but it costs more to maintain the pond, since water is not free in the Philippines. Even if the pond is made, the costs of tilapias are a heavy burden to local families.
2. An epidemic may occur that will annihilate all tilapias in the pond. Breeding varieties of fish in the pond can prevent much damage, but this, too, may be unaffordable for farmers. (It is very important to breed species that has a different diet with tilapias as tilapias are aggressive and tends to harm other fishes.)
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Possibility 2: Creating Your Own Fish Pond (Natural Pond)
Advantages:
1. Natural ponds are economically effective since it does not cost money to build an enclosed habitat for tilapias. The pond itself may provide foods such as weeds, algae and little critters since tilapias are omnivores, and grow fine without meat.
2. See Possibility 1, Advantages #1-4.
Disadvantages:
1. Fish farms require vast amount of ponds in order to make actual profit. Enclosed Natural ponds work the best as the environment maintains itself without much external effort compared to artificial ponds. However, most ponds and rivers in Marikina are heavily polluted, which is impossible for tilapias to live in.
2. Many of the ponds and land is personally or publicly owned; permission from the owner is required, but, in many cases, the owner is unknown. Moreover, it is uncertain that the owner will allow anyone to use their pond without payment.
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Possibility 3: Selling Cooked Tilapia
Everyone loves a delicious dish so why not try cooking to escape poverty?
P.S.: There are cases when freshwater tilapias taste like soil between March and August. This is caused by the type of sea weed they eat during that period and can be removed by soaking the fish in lambanog (coconut or palm wine) one hour before cooking.
Advantages:
1. Much money can be earned by cooking tilapia depending on the dish’s quality. Most fish markets in Marikina City, Philippines, order their fishes at a prize of 75 Php/kg everyday from the province of Batangas and sell it between 95 to 99 Php/kg. If mass amount of tilapia is required, ordering from Batangas will reduce the prize.
2. Tilapias are said to be most sold between September to January (rainy season). Although further research is required for this, I presume ordering during that time might actually lower the prize a bit more, because of the boost in tilapia’s reproduction rate.
3. The dishes can provide different vitamins and minerals to poor families especially growing children.
Disadvantages:
1. The ingredients for the dish and basic cooking utensils may be expensive.
2. Multiple recipes and a good sense of taste are required for one for more income.
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Bibliography
“About our Fish.” Rain Forest Culture. 2002. 24 April 2008. <http://www.tilapia.com/Tilapia.html>.
“Caring for Tilapia.” Virgin Islands Aquaponic Institution. 24 April 2008. <http://www.growseed.org/tilapia.html>.
Elloran, Christian. Synonyms of Tilapia Jallae. 21 Feb. 2008. 24 April 2008. <http://uinen.nrm.se/Nomenclature/SynonymsList.php?ID=6914&SynCode=17533&GenusName=Tilapia&SpeciesName=jallae>.
“How to Build a Water Garden or Fish Pond.” The Water Garden. Copyright 2008. 3 May 2008. <http://watergarden.com/pages/build_wg.html>.
Jasareno, Baby. Personal interview. 28 April 2008.
Popma, Thomas and Masser, Michael. Southern Regional Aquaculture Center. Tilapia Life History and Biology. March 1999. 24 April 2008. <http://aquanic.org/publicat/usda_rac/efs/srac/283fs.pdf>.
“Raising Tilapia and Other Fishpond Tips.” EntrePinoys Atbp. 26 Sept. 2006. 3 May 2008. <http://www.mixph.com/2006/09/raising-tilapia-and-other-fishpond-tips.html>.
“Tilapia jallae (Boulenger, 1896).” ITIS Report. 23 April 2008. 24 April 2008. <http://www.itis.gov/servlet/SingleRpt/SingleRpt?search topic=TSN&search value=648184>.
“Tilapia.” Wikipedia The Free Encyclopedia. 21 April 2008. 24 April 2008. <http://en.wikipedia.org/wiki/Tilapia>.
“Tilapia.” ZipcodeZoo.com. 13 April 2008. 24April 2008. <http://zipcodezoo.com/Key/Tilapia_Genus.asp>.
Tavas, Mary. Personal interview. 2 May 2008.
Viernes, Rotchie. Personal interview. 2 May 2008.
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