APPLICATION OF BIOTECHNOLOGY FOR GENETIC IMPROVEMENT IN FISH FARMING A CASE OF AFRICAN CATFISH Clarias gariepinus

Biotechnology research and development is moving at a very fast rate. In broad terms, Biotechnology can be defined as any technological application that uses biological systems, living organisms or derivatives thereof to make or modify products or processes for specific use. This range from the use of synthetic hormones in induced breeding hybridization, production of monosex, uniparental and polyploid Molecular biology, transgenic fish to gene banking. 

CHAPTER ONE 1.0    INTRODUCTION   Biotechnology  research  and  development  are  moving  at  a  very  fast  rate.  The  subject  has assumed greatest importance in recent years in the development of agriculture and human health. The science of biotechnology has endowed us with new tools and tremendous power to create novel genes and gene type of plant, animals, including fish.  In broad terms, biotechnology can be  defined  as  any  technological  application  that  uses  biological  systems,  living  organisms  or derivatives thereof, to make or modify products or processes for specific use. This ranges from the  use  of  synthetic  hormones  in  induced  breeding,  hybridization,  production  of  monosex, uniparental and polyploidy, molecular biology, transgenic fish to gene banking.  There is considerable interest worldwide in applying genetic engineering to aquaculture (Chen and Richard 1998). One reason is that as the world catch of wild fish is rapidly approaching the estimated maximum potential harvest at 100-150 million tons, an increasing demand for marine proteins is likely to be provided by aquaculture. Another reason is that genetic engineering has a potential to  tailor fish  species for cost  efficient aquaculture production of fish  proteins, either alone or in combination with traditional breeding technique.  Due to the increase in growth rate of the world population, the demand for fish is soaring worldwide and it appears unlikely that the increasing demand  can  be  met  through  increased  natural harvests  as  many of  the  oceans and natural  freshwater  fisheries  are  being  harvested  to  their  limit.  Aquaculture  unlike  capture 

2  fisheries  requires  deliberate  human  intervention  in  the  organism  productivity  and  yields  that exceeds those from the  natural environment. Aquaculture, therefore, remains the last hope for providing enough fish for the world, but with limited land and water space.  Aquaculture biotechnology, therefore, has come to have a key role to play as it can make a great contribution  to  improving  aquaculture  yields.  The  application  of  biotechnology  to  various production  systems  does  not  come  without  its  negative  impacts  but  even  still,  the  merits  far outweigh the associated concerns because the techniques are constantly being developed thereby reducing  the  negative  impacts  thereof.  Therefore,  there  is  need  to  adopt  biotechnological practices  if  the  world  is  to  stand  any  chance  of  achieving  food  security.  The  application  of biotechnology in the aquaculture sector is a relatively recent practice.  Nevertheless,  it  is  a  promising  area  to  enhance  fish  production.  The  increased  application  of biotechnology tools can certainly revolutionize our fish farming besides its role in biodiversity. Research shows that some of the modern genetic technologies are already extensively applied by the diverse aquaculture industries, though not to the same extent for all important aquaculture species (according to FAO 1998 figures). The tremendous impact that biotechnology is having in aquaculture  has  been  particularly  obvious  in  recent  years.  Chromosome  set  manipulation techniques,  which  allow  sex-manipulation  and  sterilization,  and  transgenic  techniques  that provide  improvements  in  somatic  growth,  disease  resistance  and  cold  resistance  (Tsai,  2003; Rasmussen and Morrissey, 2007; Dunham, 2009), are clear examples of the importance of the application of biotechnology in the aquaculture industry.  Some species (common  carp, Atlantic salmon,  rainbow trout, channel catfish,  African catfish, Nile tilapia, and  the Pacific oyster) received  concentrated breeding efforts,  while other  major 

3  cultured species (Chinese and Indian carps ) received, so far, relatively limited attention, and a few  species  (blue  mussel,  white  Amur  bream,  and  milkfish)  have,  apparently,  not  been genetically improved at all. Most of the genetically improved strains reaching the aquaculture industry  were  developed  through  traditional  selective  breeding  (selection,  crossbreeding,  and hybridization). Emerging, more modern technologies for genetic manipulation seem to take 10–20  years  from  being  established  experimentally  until  applications  affect  the  industry.  Thus, chromosome-set  and  sex  manipulations  started  to  affect  the  industry  during  the  1980‘s  and 1990‘s. DNA marker technology and gene manipulations have yet hardly affected the industry. The former have not matured  yet, but  hold much  promise. The latter could have affected  the industry already had it not been restricted by public concern.   The world fisheries are in a period of  crisis.  Many  major  fish  stocks  are  showing  precipitous  declines  in  productivity  due  to overfishing  and  further  increases  are  not  anticipated  under  the  current  global  conditions  and environment.   The development of improved fish seed stocks that can contribute to increased fish production is seen  as  one  of  the  key  solutions  to  meeting  the  future  food  demands  of  the  growing  world population.  Biotechnology has opened a new window for development of genetic resources in aquaculture. Aquaculture genetics shows immense potential for enhancing production in a way that meets aquaculture development goals for the new millennium (Akankali et al., 2009).  Biotechnology has the potential to enhance reproduction and the early developmental success of culture  organism.  The  technology  is  used  in  several  different  ways  in  aquaculture  and  its application benefits both producers and consumers of aquaculture products.  Biotechnology has played an important role in the growth of aquaculture to its present state of development, and we can anticipate that biotechnology has the potential to revolutionize fish culture as we know it 

4  over the next decade or so. Biotechnology has two major roles in aquaculture: it can improve the economic efficiency of aquaculture and it can also contribute to the sustainability of aquaculture and the protection of wild stocks. The responsible and appropriate application of biotechnology will enable the development of sustainable aquaculture and facilitate the concurrent maintenance of wild stocks for their commercial, recreational and inherent aesthetic value. Due to the increase in growth rate of the world population, the demand for fish is soaring worldwide and it appears unlikely that the increasing demand can be met through increased natural harvests as many of the oceans and natural freshwater fisheries are being harvested to their limit.   Aquaculture biotechnology, therefore, has come to have a key role to play as it can make a great contribution  to  improving  aquaculture  yields.  The  application  of  biotechnology  to  various production  systems  does  not  come  without  its  negative  impacts  but  even  still,  the  merits  far outweigh the associated concerns because the techniques are constantly being developed thereby reducing  the  negative  impacts  thereof.  Therefore,  there  is  need  to  adopt  biotechnological practices if the world is to stand any chance of achieving food security. Biotechnology has the potential to enhance reproduction and the early developmental success of culture organism.  The technology is used in several different ways in aquaculture and its application benefits both producers and consumers of aquaculture product. Biotechnology provides powerful tools for the sustainable development of aquaculture, fisheries, as well as the food industry. Increased public demand for seafood and decreasin///