Lupine Publishers |Agriculture Open Access Journal
Abstract
This study was primarily undertaken to review the current status of
fish seed production at freshwater sector of West Bengal,
Bihar and Assam – three leading seed producing states of India (Figure
1) and its distribution range within the state and throughout
the country. Main emphasis of the work was to assess how far the current
practices are following the principle objectives of the
technology i.e. production and supply of quality seed out of captive
breeding. With the immediate standardization of the technology,
West Bengal farmers adopted the technology of their own (in 98% cases)
and started practicing the technology, initially through
hapa breeding and afterwards through the establishment of Chinese
hatchery. The realization of huge profit margin within a short
period (4-6 months), attracted people from diverse sectors and soon
mushroom hatcheries came, who started practicing seed
production by learning the mechanical aspects of the technology from
neighboring farmers.
The profit-making proposition attracted farmers from Assam and Bihar,
who by learning the mechanical aspects of the technology
from ignorant fish breeders of Bengal, started seed production in
captivity by hiring skilled laborer from Bengal, which continues
still today. Even today the entire hatchery operation in Bihar and part
of the hatchery operations in Assam is under the control of
hired people from Bengal. Misappropriation and profit-making proposition
[1] of the technology and subsequent deterioration of
quality starts from this point. In the subsequent years, the fish
breeders, not being apprised of their faulty breeding practices due
to want of any primary training on their part, used the technology only
for profit. In the compromization with quantity, quality lost
its fragrance and as a consequence a worthy technology became a curse in
disguise for the sector.
Within very short period of introduction of technology, the ignorant
farmers started practicing improper breeding practices
like mixed spawning, use of small number of under aged and undersized
breeding population and indiscriminate hybridization
for their profit and convenience. Mixed spawning leads to hybridization
inadvertently and ultimately affect the native gene pool.
Maintenance of small number of founder population leads to inbreeding
and the obvious genetic consequences are the increased
fry deformities (37.6%), decreased food conversion efficiency (15.6%)
and fry survival (19%). Again, the undesirable hybrids [2,3]
when find their way into natural system results in “genetic intermixing”
and affects the genetic biodiversity of the native fish fauna of
Bengal. Along with these the fish breeders are introducing alien fishes
almost every year without maintaining any code of practice.
This alien introduction and repeated use of unauthorized drugs and feeds
(composition totally unknown) severely affecting the
native biodiversity and unless checked early it may lead to the
extinction of some of the prized fishes of Bengal.
Keywords: Seed quality; Misappropriation; Mixed spawning; Genetic intermixing
Introduction
Indian carps are seasonal breeders and gonadal recrudescence
in these fishes occurs after vernal equinox i.e. on 22nd March prior
to breeding seasons [4]. These fishes develop eggs but cannot shed
them in captivity. To overcome the demerits of natural collection
of spawn, the techniques of induced breeding otherwise known as hypophysation was developed in experimental condition. The
technique later transferred to field condition, which revolutionized
the fish seed production and trade in Bengal in particular. It is
observed that Bengal fish seed producer’s/hatchery owners,
being illiterate and totally unaware of the scientific basis of the
technology; inadvertently use the technology only for profit making
purpose. In most cases the farmers learn the technology from
the neighboring farmers and there was complete absence of any
institutional transfer or training program and follow-up action. The
Bengal farmers adopted the technology very well and shouldered
the responsibility to produce more than 70% fish seed requirement
of the country. At the same time, the farmers modified and refined
the technology time to time with their innovative approach From
Bengal the technology was transferred to Assam first and then to
Bihar, while farmers of both the states visited Bengal hatcheries,
may be at the end of seventies. The farmers of both the learn the
technology from the ignorant and illiterate fish breeders of Bengal
and for establishing hatcheries in their individual states hired
skilled labors from Bengal. This indicates that initial establishment
and implementation of such a novel technology were done without
any scientific approach of program.
Now, with the standardization of the technology and entry of
more and more entrepreneurs and business sector, a competitive
approach developed among the fish seed producers. This led
the farmers to adopt some unfair means and use the technology
for profit making purpose. This includes mixed spawning,
indiscriminate hybridization (and introduction alien species from
neighboring countries. Added to this the farmers out of ignorance
never considered potency of the gland and started using immature
fishes due to scarcity of brooders during breeding seasons. All
these phenomena resulted in serious genetic consequences like
inbreeding, genetic introgression etc. The obvious consequences
are the negative impact on stock integrity and genetic biodiversity
of the native fish fauna. Target oriented research program with
strict imposition of laws need to be initiated to check the further
loss in biodiversity and maintaining sustainability.
Materials and Methods
The study conducted involving the leading hatchery owners in
some of the major seed producing districts of West Bengal, Assam
and Bihar. A questioner schedule was prepared and detailed field
information was accounted based on the schedule. Fish breeders
were interrogated and detailed information were documented
regarding the present mode of the application of the technology.
The data were compiled and presented in the text. The photographs
presented in the text were taken during the field study. Initial study
started with West Bengal as it was the pioneer state in implementing
the technology, the technology for quality seed production in
captivity. Then we proceed to Assam and Bihar as because after
standardization of the technology in West Bengal it was transferred
to the said two states from West Bengal hatcheries.
In case of Assam, the farmers turned fish breeders learn the
technology from the ignorant and illiterate fish breeders, after
visiting West Bengal hatcheries during late seventies or early
eighties. The scenario of implementation of technology in Bihar
is somewhat different. It was envisaged during visit that the
entire hatchery operation is controlled by some ignorant hired
fish breeders of Bengal, locally known as fish doctor. Even the
doctors carry entire batch of pituitary gland with them from West
Bengal. The entire operational procedure of implementation of the
technology in captivity itself indicate how such a novel technology
lost its significance within a period of 30 years and went away far
away from its original goal to produce quality seed in captivity. Out
of field study 25 hatcheries from each state were selected for and
the operational procedure was incorporated in the present paper
Results and Discussion
The quality deterioration of seed, through the implementation
of induced breeding technology, started with the following
misappropriation.
Dissemination of Technology
The quality deterioration starts with the faulty implementation
of the technology, after its discovery at the CIFA centre of Indian
council of Agriculture Research, Orissa, India. The transfer of
technology, if we count the codes of transfer of technology,
developed in the scientific laboratory, here induced breeding
technology, didn’t follow the code of practice of transfer. Here, we
may consider it as an adoption instead of transfer as because the
pioneer fish farmers turned fish breeders adopted the technology of
their own from neighbouring 1 or 2 hatchery owners, who learned
only the manual aspects of the technology from Govt. Official.
Very soon Mushroom hatcheries has come up in and around two
districts of West Bengal, India, and in most cases the fish farmers
learned only the manual aspects of the technology as there was,
practically, no initiation from the Govt. Sector and/or Institutional
level to appraise the fish breeders about scientific basis of the
technology at any level. Quality deterioration starts with the very
first step of unscientific dissemination and as the short-term profitmaking
quality is appraised, more and more people opted for
captive breeding program by learning only the manual aspects of
the technology.
Improper Potency of Pituitary Gland
At the initial stage, before the discovery of synthetic inducing
agents like Ova prim, Ova tide, Wova FH etc., pituitary gland
was the sole inducing agent. Following the principle of induced
breeding, for initiating complete spawning, a pituitary gland should
have the right potency. As indicated a rightly potent gland would
be that one which is collected from the properly matured fresh
fish i.e. fish should be in the 2+ age group and freshly collected.
Initial dependence on pituitary led to the development of a chain
comprising of gland collector, retailer and supply chain. Collectors are
hired persons by the retailers and collects gland from the
beheaded head parts of the ice preserved fish from the market. The
second phase of the quality deterioration occurs with the collection
of impotent pituitary gland about which all involved, from gland
collector to fish breeders are not concerned out of ignorance and
illiteracy. Final impact is the reduction in population size with
consequential genetic phenomenon like inbreeding, genetic drift
etc.
Brood stock – its Availability and Management
In a breeding program, the primary input is the readily
available male and female fish at the peak of their maturity stage.
Along with maturity age and size of the brood fish is also an
important consideration for the successful spawning. According
to the principle of induced breeding a brood fish in the age and
size group of 2-5 is suitable. Collection of brood stock in adequate
number from different geographical territories, cataloguing of their
geographical origin, their genetic characterization and maintaining
their pedigree record are important pre – requisites for breeding
program. These aspects are of much genetic relevance for a scientific
breeding aiming at quality seed production. Further proper feeding
of brood stock and their health maintenance are some important
management aspects. Different fish show considerable variations
in the number of eggs develop i.e. Fecundity varies. As fecundity
refers to number of eggs/kg of body weight so it is easy to assess
the requirement of brood stock for production of specific number
of eggs. The dietary intake of blood stock found to have profound
influence on maturation and fecundity of fishes. Experimental
results indicate decreased egg production (75%) when ration size
reduced to half, again decreased ration size during second half of
reproductive cycle decrease egg size (Table 1).
Table 1: Brood stock management practice in the area of study.
*(>6 species); * *Average; *** (>1500) kg.
Infrastructure for Brood Stock Raising
The available brood stock raising area, nursery, spawning pool,
hatching pool, brood stock biomass etc. available in the hatcheries
of study area was insufficient. Altogether, 84% of the hatchery
owner had insufficient area for growing of brood stock in their farm
(Table 1). Formula for calculation of the area required for brood fish
pond according to Thomas (2003) is:
ABRP = BR×1/SD, where
ABRP = Area of brood fish production pond
BR = Weight of brood fish expressed in kg
SD = Stocking density of brood fish per ha.
Source and pedigree of brood stock
The study revealed that 72% of the hatchery owners do not
have sufficient numbers of brooders to sustain the level of spawn
production in their hatchery (Table 1). The small farmers depend
entirely on outside source for collection of brood fish prior to
breeding programme. The big and medium farmers depend both
on farm raised and outside source. It was observed that 62% (average) of the total brood fish comes from farmers own pond
and the rest 38% (average) comes from outside source and share
basis prevalent among the farmers. The breeders in the hatcheries
(80%), visited during study period, are least bothered to know the
pedigree of fish stock they have for the breeding programme to be
carried out in their farms (Table 1). None of the farms were found
to maintain pedigree record of the brood stock, repeatedly using
for seed production since long back, required to avoid the mating of
close relatives. Cultured populations should be identified by using
a proper marking system. Females & males should be from two
different lines.
Culling
The practice of eliminating or culling of fish from the breeding
programme is the necessity of the modern breeding programme.
The culling of fish could be based on the criteria based on the
phenotype of fish such as growth, disease, deformity, age, size, and
most catchable fish than least catchable during harvesting. No such
activity was adopted by any of the fish seed producers of the study
area, instead one of the breeder was seen injecting a grass carp fish
for induce spawning with a tumour like lump on the skull region of
the fish (Figure 1). According to the information provided by him,
it was learnt that he has been breeding the same fish for the last
couple of years. Table1 conforms that majority of the breeders have
no idea about the importance of culling of fish from the breeding
programme. Quality deterioration finds its easy routes when a
diseased fish used as brooders.
Figure 1: Tumour like lump on upper Cephalo -thoracic region, a potent candidate as brood fish.
Feed and fertilizer
Majority of the hatchery managers do not have proper feeding
schedule for the brood stock or nursery management and provide
(80%) feed and fertilizer on monthly basis (Table 1). It is just
before the start of the breeding season there is a change in feeding
schedule. From February onwards, protein rich feed composed
of cereals, broken rice, fish meal etc., after boiling in large pot
(karai) are broadcasted in the pond arbitrarily two times a day,
without any consideration to the bodyweight. In West Bengal and
Bihar, the farmers and fish breeders are more interested in using
floating feeds, the reason, as they advocated that as the feeds are
floating so it helps them to gaze the amount of feed required by
the total biomass, besides it creates no pollution. Whatever it may
be the entire supply chain of all the aquaculture products like feed,
medicine, chemicals, probiotics and inducing agents are under
the control of some unscrupulous middleman/agents. Many a
times these products fail to fulfil the criteria of the specific needs
for which they are used. The consequences are that the users are
deprived of getting the expected results.
Table 2: Breeding Practices as adopted by the Fish breeders of Three States.
Figure 2: Need of the farmers as quantified (%) from the survey. (a=specialized training, b=Institutional Finance, c=soil and
water testing d=institutional coverage, e=organized fish seed market, f=unhealthy competition, g=exemption of taxation
during transportation, h=introduction of new species, i=change in land revenue act, j=supply of quality food, k=removal of
discrepancy in breeding program, l=supply of quality brooders m=specific aquaculture medicine).
As indicated, the actors involved in operating the captive
breeding program are totally ignorant about scientific basis of
the technology and they are using the technology only for profit
making proposition. Mixed spawning, multiple breeding (Figure
2) is the normal practice due to convenience and profit. Mixed
spawning (more than 80%), is mainly undertaken to cut the water
and electricity budget, as because in case of single species breeding,
separate breeding pool is required. Mixed spawning leads to
indiscriminate hybridization resulting in genetic introgression and
other related consequences [5].
In Bihar the entire hatchery operations are under the control
of some hired skilled labourer, but in Assam the operations are
partly under the control of some hired skill labourer from Bengal.
Not being appraised of the basic principles of the technology and to
meet the demand of the customers as also to fulfil the profit of the
hatchery owners, they adopt all sorts of misappropriation, starting
from the use of impotent gland to mixed spawning, hybridization,
multiple breeding, use of under aged diseased fishes as brood
fishes. Cross verification of some of the leading hatchery owners of
three states emphatically said that in more than 80% cases the fish
breeders adopt all sorts of misappropriation to achieve their target.
Problems & Suggestions from Farmers
a) Inadequate technical know how
b) Finance
c) Poaching, poisoning of water body
d) Labor dispute, flooding and water logging of the farm sit
e) Availability of quality pituitary gland
f) Excavation of pond in agriculture land
g) Selling of fish seed on 3rd and 4th day of incubation.
8. Suggestions from the Fish Breeders/Farmers
a) Institutional Training Program
b) Changes in Land Revenue Act.
c) Easy Finance.
d) State wise Hatchery establishment for reducing mortality
during transportation.
e) Standardization in breeding should be stopped.
f) Dishonesty in breeding should be stopped.
g) Some progressive farmer suggested that household waste
water should be drained to a common place on a cluster basis and
may be used for backyard fish farming so that some kind of social
fishery might be developed. The farmer also suggested that suitable
drainage plan should be incorporated during the plan making of
house building.
h) Poaching should be stopped.
i) Management of water quality.
j) Subsidy in electricity.
Conclusion
The study indicates that how proper and scientific dissemination
of a technology is important for sustenance of the technology. Here,
illiteracy, ignorancy on the part of fish breeders about the scientific
basis of the technology plays a negative role against its proper
implementation. This is the 1st phase of the beginning of quality
deterioration of fish seed in captivity. The initial phase starts with
use of impotent gland in most of the breeding program. With the
increasing demand for quality carp seed from captivity, the demand
for pituitary glands were becoming more ex-pensive and their
availability is decreasing. Often, batches of these pituitaries are
bad as they are collected from the market where dead fishes are
preserved under ice. Decrease in their potency is leading to failure in
spawning. To overcome these problems, induced spawning of carps
and other important fishes, in many countries, are now carried
out with GnRH or its analogue [6] which release endogenous GTH
and effects spawning in a much confident manner than the crude
pituitary extract.
Besides, Pituitary extract very often also contains pathogenic
micro-organisms causing infection in fishes. Moreover, pituitary
GTH is glycoprotein in nature and is extremely sensitive to
temperature denaturation. Hence, GnRH is no doubt a better
alternative for induced spawning. But there is one problem with
GnRH use; its activity is inhibited by endogenous dopamine.
Dopamine occupies GnRH-receptor and thus blocked its action on
pituitary gonadotroph cells. Use of domperidone (or pimozide),
a dopamine antagonist, increases GnRH-receptor capacity, thus
enhancing GnRH responsiveness [7]. Therefore, for induced
ovulation, together with salmon GnRH-analogue, pimozide (antidopamine)
has been use. On the basis of information, Ova prim, a
commercial product has been prepared by the Syndel Laboratories,
Canada, which is now marketed by Glaxo Laboratories Ltd for
induced breeding of fish.
Though Assam breeders exclusively use synthetic hormones,
the West Bengal and Bihar breeders still use the pituitary extract
as the primary inducing agent. They claim that pituitary is more
effective in stripping and also put blame about the ineffectiveness of
synthetic hormone in many cases. Comparative study on the efficacy
of two inducing agent on individual species may help in dissolving
confusion.Though brood stock can maintain on maintenance ration
but recent information, as revealed by various experimental results,
indicate deficiency of certain dietary ingredients such as fatty
acids (PUFA), vitamins, trace elements, can have negative impact
on maturation, breeding, spawning, larval vigor and survivality.
Keeping in mind that nutritional requirement varies according to
species, proper experiment should be designed to formulate right
food for individual brood stock so that supply of quality seed will be
ensured to the farming sector.
Experimental study on wild stocks of C. catla represent a
diversified genetic resource and indicates that in situ management
practices, such as preventing the wanton capture of fish and creating
sanctuaries for protecting small stocks such as those in major rivers,
can help maintain and conserve the present diverse gene pool.
Hatchery owners are accustomed to operating negative selection
and polygynous breeding systems in which some males mate with
many females year after year, resulting in genetic deterioration that
subsequently cause a negative impact on aquaculture production.
Based on our present findings, hatchery owners can collect their
brood fish or replace their existing breeding populations with
genetically diverse fish from stocks like those in the rivers and
increase their effective breeding populations and thus improve
the aquaculture production. However, the strict implementations
of correct management practices are essential to maintaining the
genetic diversity of the natural stocks.
Table 3: Faulty Approaches in Breeding practice & related criteria.
A further important point is that breeding between two
genetically discreet or distant populations may have a positive
impact on aquaculture production. As indicated in Table 3 due
to dire scarcity of brood fish, except large hatchery owners
there was no organized brood stock management practice, the
fish breeders adopt all sorts of misappropriation to manage the
customers demand. This create some important avenues for
quality deterioration of seed in captivity, Mixed spawning, another
profit-making approach by the fish breeders, leads to genetic
introgression [8] among the genetically flexible different species of
fish [9] while repeated use of small number of founder population
for seed production results in inbreeding. All these faulty breeding
practices throughout the years has eroded the qualitativeness of the
technology, as established by the frequent claim by the seed buyers
regarding the poor performance in terms of growth in particular.
Other related criteria like use of skewed sex ratio and immature
brood fish are also producing negative impact against quality of
seed. A consolidated program from Govt. and institute level need to be
initiated for general appraisal of the misappropriation with
implementation of suitable laws banning the faulty practices can
provide sustainability to such a novel technology [10].
In all, it can be said that the first criteria to consider the
development of aquaculture sector is the steady availability of
quality seed locally (within the states and country) to meet the
requirements of the industry. Where ever this has not been possible,
seeds and /or brood stock may be introduced through certification.
It is encouraging to observe that we are in a stage where the
emphasis is slowly shifting from quantity to quality. Only in very
recent years farmers began to realize the importance of quality
seed i.e. pathogen free uniform size seed to remove their sufferings
and to maximize production. It may not be entirely wrong to say
that this shift in emphasis (attitude) to seed quality has come about
largely because of the recurrent disease problems that has besieged
the aquaculture industry especially shrimp and fresh water prawn.
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