CHAPTER1 INTRODUCTION Bangladesh is ariverine country. It contains numerous freshwater, brackish water and saline waterbody including haor, baor, beel, marsh, swamp, canal, pond, lake, river,estuary and sea. In inland fishery production Bangladesh is occupied fourthplace just after China, India, and Myanmar and fifth place in closed waters(FRSS, 2016). Fisheries sector are indivisible from the life and lifecycle ofthe people of Bangladesh.
It contributes 3.65% to the national GDP and almostone-fourth (23.81%) to the agricultural GDP and 2.01% of the total proteinsupply in the diet of the people of Bangladesh (DOF, 2016). About 1.5 millionpeople are directly employed by this sector (DOF, 2016).About 260 fishand 24 prawn species are comprehend to inhabit in the freshwaters of Bangladeshwith 12 exotic fish species have been documented (IUCN, 2000, pp. 1–116; Rahman, 1989, pp.
1–352). There are approximately 40–50small indigenous fish species which rise to a highest length of 25 cm (Felts, Rajts, & Akhteruzzaman, 1996,pp. 1–41). About 511 marine species together exist within Bangladeshi waters (Murshed-E-Jahan, Belton, & Viswanathan, 2014).Marine fisheries outgrowth is only 16.
28% of the national fish production (FRSS, 2016). Total area ofinland water bodies is 4700795 ha where closed and open water resourcescomprises 794361 ha and 3906434 ha respectively (DoF, 2016). Fisheries are undoubtedlythe most important company in the budget and about 16.5 million individuals areindirectly reliant on fisheries related actions for their living (Ministry ofFinance, 2013; DoFB, 2011, 2013). In the fiscalyear 2014-2015, foreign income from the fisheries sector is 1.92%. About 11%inhabitants of our country directly or indirectly depend for their employmenton fisheries and aquaculture sectors (DoF, 2016). From 2000 to 2016, aquacultural volume enhanced from 7, 12,640 to 20, 60,408 MT, a much largerquantity than wild capture production (1.
023 million t) in 2016(Shamsuzzamanet al. 2017).The highlyproductive aquatic biodiversity of the Bangladesh has been associated to theworld’s one of the biggest wetlands (Bengal Delta) and three large riversystems (Ganges, Brahmaputra and Jamuna) that rise from the Himalayan Mountainsinto the Bay of Bengal. Huge inland fisheries resources provide fish and otheraquatic flora and fauna to the millions of living people in the Delta (Hossain,2014).
Leading Rangpurdistrict is a temper liable area. Water retaining capability of the pond islessening day to day. As a consequence, the number of seasonal ponds (60%, BBS.2000) is arising. About 55% ponds are seasonal in the northern districts ofBangladesh of which 60% contained water for 4-6 months while 40% absorbed for6-9 months in a year and even more in some areas. Villagers normally, make useof these little water bodies for their domestic purposes while some are stillbanished due to their neglectful and vagrant mentality.Nilphamariregion is such an area where this culture strategy is the most wanted andadequate for all types and kinds of fish farmers for fish production andeconomic return.
This analysis will be desired to give financial backup formarginal fish farmers and a source of quick return of money also. From theaquaculture point of view, those ponds have a high value for practicing fishculture including the species which have concise life cycle, hurried growth andrequire minimum inputs, such as Vietnamese koi (Anabas testudineus), Shing (Heteropneustesfossilis), genetically improved farmed tilapia (GIFT), Silver barb (Barbodes gonionotus), and Magur (Clarias batrachus), sharputi (Puntius sarana).To assure themaximum utilization of those ponds, above species were chosen for ensuring thehighest production. The demands for those fishes are owing to their taste andmedicinal values. The belief is that there are beneficial and medicinal criteriain those fishes which are healthful for patients and convalescents by Mookerjeeand Mazumder (1950). But absence of knowledge of proper culture methods andscarcity of good fish fry of suitor species at required time are found to besome of the chief constrains at up to date time to propagate the culturemethods of these species have yet not been optimize and figure out specially inNorthern region of Bangladesh. In the past we were relayed upon forfish utilization only from the natural open water reserves but this dependencyis out of control due to gradual fragmentation of open water bodies as well asbooming our population density (Hoque etal. 2017).
Since the expansion offish production from our beels, canals, lakes, river and estuaries are generallyto be complicated; we need to relay on aquaculture especially on pondaquaculture for enhancing of our population demand, employment generation andpoverty reduction of Bangladesh. Although the people of Bangladesh areincreasing geometrically but our reserves are not increasing in the same manner(Hoque et al. 2017).Polyculture is the culture of two ormore fish species within a confined aquaculture environment. Every polyculturepractice in ponds.
The inspiring assumption is that the production of fish inpond may be maximized by culturing a mixture of species of different food andfeeding habits. The combination of fish allows better utilization of sufficientnatural food grown in a pond. It is the system where fast growing species withdifferent feeding habit are cultured in the same pond (Jhingran, 1975).The probability of increasing fishproduction per every unit area, via polyculture, is considerable, when comparedwith monoculture systems of fish. Different species aggregations in polyculturesystem effectively furnish also to improve the pond environment.
Some of thefish species grown in carp ponds include paddlefish, tilapia and big head carp.In considering pond polyculture, certain aspects such as feeding, harvest andmarketing should be emphasized first. Statistics show that there was noinformation on polyculture practice of Vietnamese koi (Anabas testudineus) in Bangladesh.In Bangladesh aquaculture, thereare approximately 92 species of exotic fishes are cultured (Bijukumar, 2000)and provides about 17% to global diet aquaculture production (Shelton and Rothbard,2006). Koi fishery contributed about 2.8%of total pond catch since the 1980s (DoF, 1992) and in present years it reducesto 0.85% (DoF, 1999) to the total pond catch.
In our country Koi is a smallnative indigenous species. It looks like greenish in appearance. Earlier the native koi was verymuch plentiful in almost all the freshwater body in our country (Mahmood,2003).Now a day this species has been reducing day by day due to degradation of naturalwater body and its growth rate in the farmer’s culture pond are not expectableas per need For thisreason Thai koi (Anabus testudineus)had been brought in 2002 from Thailand for higher taste, growth, nutritiousvalue and a high market price (Alam et al.
2006). Butit has lost its higher growth rate capability features due to inbreeding in thefry production period.To overcome from this problemSharnalata Agro Fisheries Limited has introduced Vietnamese Koi (Anabas testudineus) in 2010 which isvery faster growth rate compare to Thai Koi. The color of Vietnamese Koi (Anabas testudineus) is whitish.
This koican be culture in pond as Thai Koi. Vietnamese koi eat commercial feed as ThaiKoi. As Vietnamese Koi (Anabastestudineus) is a newly opened species in aquaculture of Bangladesh, no recordyet been sufficient to us about its culture technique, stocking density, foodand feeding behavior, breeding and disease occurrence. It can tolerate harshenvironmental conditions such as wide range of temperature, low oxygen andother poor water conditions (Habib and Hasan 1994).It has some special faces such as quickergrowth rate, auxiliary respiratory organs, shorter culture period (within 3-4months marketable size) and advanced survival rate (Kohinoor & Zaher 2006; Jannatet al. 2012).
It contains great amount of iron,copper and easily edible poly-unsaturated fats and many indispensable aminoacids (Saha 1971, Kohinoor et al.1991). Chanchal et al. (1978) conducted a test on somepoint of biology of Anabas testudineus.Islam (2007) carried out an experiment on physico-chemical condition andoccurrence of some zooplankton in a pond of Rajshahi University.
In our countrysustainable development of aquaculture is necessary in order to enhance theproduction. For this reason, Vietnamese Koi can play a vital role to have moreproduction considering with little capital investment but maximum economicreturns. The causesbehind the greater extension of vietnami Koi culture in Bangladesh are: a) Thefish can bear our atmosphere easily; b) It is cultivableunder high stocking concentration; c) Itis cultivable in deep or low water; d)They can continue in little oxygen level; e) It can be promoted at alive condition; f) Crop can be achieved within 3-4 months; g) Since it is beneficial and delicious so, it can be used as patient diet.It is necessary to examine the growth potential of Vietnamesekoi and to compare with the other koi fish accessible in Bangladesh. Thepresent research has been undertaken to expand a practical and economicallyfeasible methodology for bunch production of A. testudineus undercontrolled grow out polyculture technology. This technology is a good knowledgein aquaculture to meet up the protein shortage and socio-economic position ofthe common people of Bangladesh (Chakraborty et al. 2014).
Hence, thisstudy has been pictured and proposed to make out these research findings atfishermen’s field as well as to corroborate the technologies. As Vietnamese Koi(Anabas testudineus) is a freshlyintroduced species in aquaculture of Bangladesh, no information yet beensufficient to us about its culture practice, stocking density, food habit andfeeding habit, breeding and disease prevalence (Hoque et al. 2017). OBJECTIVES OF THE STUDYØ Todetermine the effects of stocking density on the growth performances ofVietnamese Koi (Anabas testudineus)under the polyculture system in farmers seasonal miniponds.
Ø Toevaluate the effects of stocking density on the water quality parameters of thecultured farmers seasonal miniponds andØ Toassess the benefit cost ratio of the cultured technology.