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Welcome to Expert Topic. Each issue will take an in-depth look at a particular species and how its feed is managed.

TILAPIAEXPERT TOPIC

1 Tilapia: adaptable from fingerling to fillet

Originating from the lakes of Eastern, Central and Western Africa, the Nile tilapia (Oreochromis niloticus) was first

introduced to developing countries as a cheap, easy way for subsistence farmers to provide their families with enough protein. With improved production techniques and methods of controlling its flavour, the fish became more of a mainstream product. Communities of migrants from these coun-tries then created a market for tilapia in the developed nations they had moved to, and

finally a taste for the fish spread amongst the locals.

With a mild, unintrusive flavour, Nile tilapia lends itself readily to a wide range of dishes and cuisines. It’s pretty adaptable from the farmer’s point of view, too. Omnivorous yet predominantly vegetarian, tilapia grow quickly on a diet lower in protein and higher in carbohydrates than that required by many carnivorous farmed species. They are also relatively resistant to disease and poor water quality, and they breed easily.

Keeping mixed-gender groups in ponds can result in lots of stunted offspring compet-ing for food and space. There are two main ways to fix this. You could try sex-reversal. Administering hormones in their feed at an

early stage ensures the fish all grow up as males. This has an added benefit, owing to the fact that males of this species grow twice as fast as females.

Alternatively, you could continue to raise them in mixed-gender groups, but in cages. Nile tilapia needs a bowl-like depression in a sandy substrate in which to fertilise their eggs and from which to gather them up in their mouths to brood them. In a cage, even if any eggs do get fertilised, they will simply fall through the mesh and be lost. Being both easier and cheaper than sex-reversal, the cage method is employed across China, Indonesia and much of Central and South America.

Source: FAO

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2 Tilapia survey demonstrates GAA’s commitment to responsible aquaculture

Since its inception in 1997, The Global Aquaculture Alliance’s phi-losophy has been to proactively identify the challenges facing aqua-

culture and to implement practical solutions that lead to continual improvements over time.

One such challenge is the use of antibiot-ics in aquaculture. Restrictions on antibiotic use are addressed in great detail in both the Best Aquaculture Practices (BAP) finfish and

crustacean farm standards and BAP seafood processing plant standards.

On June 2, GAA further demonstrated its commitment to responsible aquaculture by publishing a survey to gather first-hand information on the use of antibiotics in tilapia farming, the results of which will educate the evolving Best Aquaculture Practices (BAP) program.

An invitation to take the 11-question survey was delivered to about 125 repre-sentatives of BAP-certified tilapia farms and processing plants located in China, Columbia, Costa Rica, Ecuador, Guatemala, Honduras, Indonesia, Mexico, Thailand and Vietnam.

This survey primarily concerns the use of antimicrobials listed by the World Health Organisation (WHO) as critical to human

health. Some of these substances are permit-ted for veterinary use. But there are concerns that overuse could potentially, by spreading resistance, reduce the effectiveness of human antimicrobial therapy. Thus, subject to the survey results, GAA will seek by year’s end to modify the tilapia-specific section of the BAP finfish and crustacean farm standards to exclude the use of antimicrobials listed by the WHO as critical to human health.

Some experts feel that antimicrobials listed by the WHO as critical to human health should be excluded from use in tilapia farm-ing. Other experts feel that these antibiotics are critical tools for disease treatment and animal welfare. BAP-certified tilapia farms and processing plants are encouraged to take the survey, which is anonymous.

Tilapia production in India: present status and prospects

by Dr B Laxmappa, Fisheries Development Officer, Department of Fisheries, India

Tilapia are now the world’s second most popular group of farmed fish after carp. Worldwide production exceeded 3.9 million tonnes in 2012 according to FAO and demand continues at a steady pace. Geographically Tilapias are the

most widespread species for aquaculture production in the world. Tilapia, a native to Africa and Middle East has emerged as one of the most internationally traded food fishes in the World. Around 20 countries are farming Tilapia, with China, Egypt, Indonesian Philippines, Thailand and Brazil taking the lead.

Tilapia belongs to the family Cichlidae under order Perciformes and has recently been classified into three genera, based on parental incubation of eggs. The species of the genera Sarotherodon and Oreochromis are mouth brooders, while Tilapia incubate eggs in a ‘nest’ built on the bottom of a lake or pond. There are about 70 species of Tilapia, of which eight species are used in aquaculture worldwide (Table: 1). One of the eight cultured species is Nile Tilapia, a relatively large cichlid fish introduced to several countries outside its natural range e.g. Brazil, Australia, Bangladesh, Sri Lanka and India.

Present status India is a vast country in terms of natural resources and considered

one of the most biodiverse countries in the world. The Indian mainland is drained by 15 major, 45 medium and over 120 minor rivers, besides numerous ephemeral streams. The diverse river systems in India har-bour one of the richest fish germplasm resources in the world. Official records show that O. mossambicus was first introduced to India from Sri Lanka in 1952 and thereafter stocked in several reservoirs in southern India for production enhancement.

O. niloticus was introduced to India in late 1987. The aquaculture of O. niloticus expanded in the southern region of the country, especially by private entrepreneurs. In 1995, Vorion Chemicals Ltd. Chennai claimed high production of hybrid red Tilapia, popularly known as golden Tilapia. However, production collapsed for unknown reasons. Culture of O. niloticus is now gearing up, particularly in Andhra Pradesh, Orissa and West Bengal, and the fish is now distributed to many states particularly the coastal areas.

Cultivated Tilapia are typically hybrids between O. niloticus and other closely related species native to Africa. O. niloticus are one of the easiest and most profitable fish to farm, in part because they are omnivorous and can be fed a diet derived exclusively from plants. O. niloticus and other fish that feed on vegetable materials offer a much more ecologically sound and environmentally friendly means of provid-ing humankind with an abundance of nutritious and delicious fish. There have been frequent escapes of Tilapia from aquaculture facilities due to recurring floods or inadvertent releases. Tilapia now forms a part of the fish fauna in the Godavari, Krishna, Cauvery, Yamuna and Ganga Rivers.

Presently in many rivers particularly the Ganga River and Krishna River system, the proportion of Tilapia production is about 10-48 percent of the total fish species. However, Tilapia holds vast promise to become an important species for aquaculture in India, considering the demand for more fish. There are many unpublished data about

the availability of Tilapia in tanks, reservoirs and rivers in many states in India. In the Kolkata Wetlands, some farmers are producing mono-sex Tilapia on a commercial scale in waste-water. In Andhra Pradesh Tilapia culture is practised in an area of around 1000 acres.

As the demand for fish increases, diversification of species in aqua-

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culture by including more species for increasing production levels has become necessary. Introduction of Tilapia in Indian culture systems is advantageous because it represents a lower level in the food chain, and thus its culture will be economical and eco-friendly. Mono-sex culture of Tilapia is advantageous because of faster growth and the larger and more uniform size of males.

Government supportTilapia is farmed widely in the whole of Asia, with the exception

of India. The Government of India has allowed Tilapia farming recently but with specific guidelines. Farms have to obtain a permit/license from the Government to carry out the farming. Farming is allowed only with mono-sex male Nile Tilapia or its hybrids. Cage culture is permitted in reservoirs where there is an established stock of Tilapia. In cages, use of floating feeds with a minimum protein content of 25 percent is encouraged. The guidelines also specify bio-security measures to pre-vent escapees. In the case of hatcheries and nurseries, permits are also required and they may only use brood stock from approved foreign and Indian companies.

In India, O. mossambicus has been widely cultured in states including Kerala, Andhra Pradesh and Odisha for the last 30 years. The Marine Products Export Development Authority (MPEDA) has chalked out a plan to culture O. niloticus in Kerala and Andhra Pradesh.

The Rajiv Gandhi Centre for Aquaculture (RGCA), the Research and Development arm of the MPEDA, Government of India also organised a one-day international seminar on Tilapia Aquaculture and Trade, the ‘India Tilapia Summit 2014’ in December 2014 in Andhra Pradesh to popularise and promote Tilapia culture in the country.

ProspectsIndia has enormous potential for aquaculture of Tilapia. Numerous

freshwater and brackish water ponds, lakes and reservoirs suitable for Tilapia culture are available in the country. The Rajiv Gandhi Centre for Aquaculture (RGCA) in Vijayawada, Andhra Pradesh started producing seedstocks of this variety three years ago based on technology adopted from the World Fish Centre in Malaysia. The centre already has a stock of around one million seed and is capable of meeting demand from other states. O. niloticus is in high demand not only on the local market but also in the US and the European Union.

The development of Genetically Improved Tilapia (GIFT) technol-ogy is based on traditional selective breeding and is meant to improve commercially important traits of tropical farmed fish, which is a major milestone in the history of Tilapia aquaculture. The Kerala and Andhra Pradesh governments recently issued directives allowing the farming of O. niloticus.

To encourage entrepreneurs, the National Development Board (NFDB) is also providing financial subsidies for Tilapia culture in the country. For species diversity, Tilapia is one of the most suitable alterna-tive species for Indian aquaculture. In future Tilapia will be the cheapest protein food source in India even for people below the poverty line.

References available on request

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Table 1: World-wide aquaculture tilapia species

Sl. No. Common name Scientific name

1 Nile tilapia Oreochromis niloticus (Linnaeus 1757)

2 Mozambique tilapia O. mossambicus (Peters 1852)

3 Blue tilapia O. aureus (Steindachner 1864)

4 Zanzibar tilapia O. hornorum (Trewavas 1966)

5 Gallilee tilapia Sarotherodon galilaeus (Hasselquist 1757)

6 Black-chinned tilapia S.melanotheron (Ruppel 1852)

7 Redbreast tilapia Tilapia rendalii (Boulenger 1896)

8 Red-belly tilapia T. zillii (Ge vais 1848)

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