CHAPTER waters (Murshed-E-Jahan, Belton, & Viswanathan, 2014). Marine

CHAPTER
1

 

INTRODUCTION

 

Bangladesh is a
riverine country. It contains numerous freshwater, brackish water and saline water
body including haor, baor, beel, marsh, swamp, canal, pond, lake, river,
estuary and sea. In inland fishery production Bangladesh is occupied fourth
place just after China, India, and Myanmar and fifth place in closed waters
(FRSS, 2016). Fisheries sector are indivisible from the life and lifecycle of
the people of Bangladesh. It contributes 3.65% to the national GDP and almost
one-fourth (23.81%) to the agricultural GDP and 2.01% of the total protein
supply in the diet of the people of Bangladesh (DOF, 2016). About 1.5 million
people are directly employed by this sector (DOF, 2016).

About 260 fish
and 24 prawn species are comprehend to inhabit in the freshwaters of Bangladesh
with 12 exotic fish species have been documented (IUCN, 2000, pp. 1–116; Rahman, 1989, pp. 1–352). There are approximately 40–50
small 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 of
inland water bodies is 4700795 ha where closed and open water resources
comprises 794361 ha and 3906434 ha respectively (DoF, 2016). Fisheries are undoubtedly
the most important company in the budget and about 16.5 million individuals are
indirectly reliant on fisheries related actions for their living (Ministry of
Finance, 2013; DoFB, 2011, 2013).

 

In the fiscal
year 2014-2015, foreign income from the fisheries sector is 1.92%. About 11%
inhabitants of our country directly or indirectly depend for their employment
on fisheries and aquaculture sectors (DoF, 2016). From 2000 to 2016, aqua
cultural volume enhanced from 7, 12,640 to 20, 60,408 MT, a much larger
quantity than wild capture production (1.023 million t) in 2016(Shamsuzzaman
et al. 2017).

The highly
productive aquatic biodiversity of the Bangladesh has been associated to the
world’s one of the biggest wetlands (Bengal Delta) and three large river
systems (Ganges, Brahmaputra and Jamuna) that rise from the Himalayan Mountains
into the Bay of Bengal. Huge inland fisheries resources provide fish and other
aquatic flora and fauna to the millions of living people in the Delta (Hossain,
2014).

Leading Rangpur
district is a temper liable area. Water retaining capability of the pond is
lessening 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 of
Bangladesh of which 60% contained water for 4-6 months while 40% absorbed for
6-9 months in a year and even more in some areas. Villagers normally, make use
of these little water bodies for their domestic purposes while some are still
banished due to their neglectful and vagrant mentality.

Nilphamari
region is such an area where this culture strategy is the most wanted and
adequate for all types and kinds of fish farmers for fish production and
economic return. This analysis will be desired to give financial backup for
marginal fish farmers and a source of quick return of money also. From the
aquaculture point of view, those ponds have a high value for practicing fish
culture including the species which have concise life cycle, hurried growth and
require minimum inputs, such as Vietnamese koi (Anabas testudineus), Shing (Heteropneustes
fossilis), genetically improved farmed tilapia (GIFT), Silver barb (Barbodes gonionotus), and Magur (Clarias batrachus), sharputi (Puntius sarana).

To assure the
maximum utilization of those ponds, above species were chosen for ensuring the
highest production. The demands for those fishes are owing to their taste and
medicinal values. The belief is that there are beneficial and medicinal criteria
in those fishes which are healthful for patients and convalescents by Mookerjee
and Mazumder (1950). But absence of knowledge of proper culture methods and
scarcity of good fish fry of suitor species at required time are found to be
some of the chief constrains at up to date time to propagate the culture
methods of these species have yet not been optimize and figure out specially in
Northern region of Bangladesh.

 

In the past we were relayed upon for
fish utilization only from the natural open water reserves but this dependency
is out of control due to gradual fragmentation of open water bodies as well as
booming our population density (Hoque et
al.  2017). Since the expansion of
fish production from our beels, canals, lakes, river and estuaries are generally
to be complicated; we need to relay on aquaculture especially on pond
aquaculture for enhancing of our population demand, employment generation and
poverty reduction of Bangladesh. Although the people of Bangladesh are
increasing geometrically but our reserves are not increasing in the same manner
(Hoque et al. 2017).

Polyculture is the culture of two or
more fish species within a confined aquaculture environment. Every polyculture
practice in ponds. The inspiring assumption is that the production of fish in
pond may be maximized by culturing a mixture of species of different food and
feeding habits. The combination of fish allows better utilization of sufficient
natural food grown in a pond. It is the system where fast growing species with
different feeding habit are cultured in the same pond (Jhingran, 1975).

The probability of increasing fish
production per every unit area, via polyculture, is considerable, when compared
with monoculture systems of fish. Different species aggregations in polyculture
system effectively furnish also to improve the pond environment. Some of the
fish species grown in carp ponds include paddlefish, tilapia and big head carp.
In considering pond polyculture, certain aspects such as feeding, harvest and
marketing should be emphasized first. Statistics show that there was no
information on polyculture practice of Vietnamese koi (Anabas testudineus) in Bangladesh.

In Bangladesh aquaculture, there
are 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 reduces
to 0.85% (DoF, 1999) to the total pond catch.

 

In our country Koi is a small
native indigenous species. It looks like greenish in appearance. Earlier the native koi was very
much 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 natural
water body and its growth rate in the farmer’s culture pond are not expectable
as per need For this
reason Thai koi (Anabus testudineus)
had been brought in 2002 from Thailand for higher taste, growth, nutritious
value and a high market price (Alam et al.
2006). But
it has lost its higher growth rate capability features due to inbreeding in the
fry production period.

To overcome from this problem
Sharnalata Agro Fisheries Limited has introduced Vietnamese Koi (Anabas testudineus) in 2010 which is
very faster growth rate compare to Thai Koi. The color of Vietnamese Koi (Anabas testudineus) is whitish. This koi
can be culture in pond as Thai Koi. Vietnamese koi eat commercial feed as Thai
Koi. As Vietnamese Koi (Anabas
testudineus) is a newly opened species in aquaculture of Bangladesh, no record
yet been sufficient to us about its culture technique, stocking density, food
and feeding behavior, breeding and disease occurrence. It can tolerate harsh
environmental conditions such as wide range of temperature, low oxygen and
other poor water conditions (Habib and Hasan 1994).

It has some special faces such as quicker
growth rate, auxiliary respiratory organs, shorter culture period (within 3-4
months marketable size) and advanced survival rate (Kohinoor & Zaher 2006; Jannat
et al. 2012). It contains great amount of iron,
copper and easily edible poly-unsaturated fats and many indispensable amino
acids (Saha 1971, Kohinoor et al.
1991).

 

Chanchal et al. (1978) conducted a test on some
point of biology of Anabas testudineus.
Islam (2007) carried out an experiment on physico-chemical condition and
occurrence of some zooplankton in a pond of Rajshahi University. In our country
sustainable development of aquaculture is necessary in order to enhance the
production. For this reason, Vietnamese Koi can play a vital role to have more
production considering with little capital investment but maximum economic
returns.

 

The causes
behind the greater extension of vietnami Koi 
culture in  Bangladesh are:  a)  The
fish can  bear  our atmosphere easily; b) It is cultivable
under high  stocking concentration; c) It
is 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 Vietnamese
koi and to compare with the other koi fish accessible in Bangladesh. The
present research has been undertaken to expand a practical and economically
feasible methodology for bunch production of A. testudineus under
controlled grow out polyculture technology. This technology is a good knowledge
in aquaculture to meet up the protein shortage and socio-economic position of
the common people of Bangladesh (Chakraborty et al. 2014).

Hence, this
study has been pictured and proposed to make out these research findings at
fishermen’s field as well as to corroborate the technologies. As Vietnamese Koi
(Anabas testudineus) is a freshly
introduced species in aquaculture of Bangladesh, no information yet been
sufficient to us about its culture practice, stocking density, food habit and
feeding habit, breeding and disease prevalence (Hoque et al. 2017).

 

 

 

 

 

 

 

 

 

 

OBJECTIVES OF THE STUDY

Ø  To
determine the effects of stocking density on the growth performances of
Vietnamese Koi (Anabas testudineus)
under the polyculture system in farmers seasonal miniponds.

Ø  To
evaluate the effects of stocking density on the water quality parameters of the
cultured farmers seasonal miniponds and

Ø  To
assess the benefit cost ratio of the cultured technology.