Freshwater prawns*

Freshwater prawn farming the world
over has registered increase in the past
decade. In India, a spurt in freshwater
prawn farming activities can be seen in
the recent years. The objective of the
symposium was to evaluate globally the
progress made and to critically analyse
the constraints and shortcoming in freshwater
prawn farming and research. K. V.
Thomas, Minister for Fisheries and Tourism,
Government of Kerala while inaugurating
the symposium, stressed on the
importance of freshwater prawn farming
in India, especially in Kerala. He expressed
concern over the pollution of the
freshwater bodies in the country and suggested
a scheme for cleaning Vembanad
Lake, one of the largest lakes in the
country.
The business session of the symposium
started with a keynote address by
Michael New (European Aquaculture
Society, UK). In the address, New reviewed
the current global status of freshwater
prawn farming with comments on
the statistical information available. Going
by statistical information of FAO for
2001, India produced 24,230 mt of the
popular freshwater prawn variety Macrobrachium
rosenbergii, standing at the
3rd position after China and Vietnam,
which produced 128,338 and 28,000 mt
respectively. He predicted that national
production of scampi in India will be
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CURRENT SCIENCE, VOL. 85, NO. 10, 25 NOVEMBER 2003 1397
well above 50,000 mt/year by 2010. After
the keynote address, status papers of
different countries were presented. Melkar
N. Tayamen (National Freshwater
Fisheries Technology Centre, Philippines)
presented the status paper of giant freshwater
prawn M. rosenbergii programmes
in the Philippines. He gave a brief update
of the technology development of freshwater
prawn with emphasis on the Bureau
of Fisheries and Aquatic Resources,
national programmes and strategies commercialization.
Nguyen Thanh Phuong
(College of Aquaculture and Fisheries,
Cantho University, Vietnam) pointed out
that Vietnam had 90 prawn hatcheries by
the end of 2002 and produced over 115
million post larvae. The Vietnam model
was notable due to its simplicity, limited
use of water and artemia, high producti
vity up to 50 to 75%, survival rate and
high profit. A. M. Jayasekara (FAO expert)
mentioned that the Government of
Sri Lanka had envisaged bringing 300 ha
of area for freshwater prawn farming in
the country. It is planned to construct a
new hatchery with a capacity of 4 million
post larvae annually under the ADBfunded
Aquatic Resources Development
and Quality Improvement Project. Ra
hima Nazar stated that Bangladesh had
about 40,000 cold water shrimp farms
covering 1,70,000 ha and 1,05,000 Golda
farms covering 30,000 ha. The Department
of Fisheries of Bangladesh Government
has established the Fish Inspection
and Aquaculture Control Act. The status
paper of freshwater prawn culture in
Brazil prepared by Wagner C. Valenti
(Savo Polo State University, Aquaculture
Centre, Brazil) was presented by M. N.
Kutty. M. rosenbergii is the only species
in the small farms concentrated in the
south-east region of Brazil. However research
projects are being carried out with
developed technology to produce the native
species M. amazonicum. Monoculture
and polyculture with Tilapia were
performed. Productivity varied from
1000 to 4500 kg/ha/year. Status of freshwater
prawns culture in China with special
reference to the high density culture of
M. nipponenus prepared by Miao Weimin
(Freshwater Fisheries Research Centre,
China) was presented by Michael New.
David Yasharian (Aquaculture Research
Centre, Kentucky State University, USA)
reported that the culture of Macrobrachium
in temperate zones offered positive
opportunities despite the inability to
culture year round. Farming with the best
management practices was by compiling
factors such as evaluating and maximizing
the relative contributions of natural
feeds, facts of artificial substrates on
growth and prawn population structure
and grading of animals prior to pond
stocking to reduce heterogeneous individual
growth. Using best management
practices, production of 1500–1800 kg/ha
has been achieved in commercial ponds
on 110 days. J. Bojan Marine Products
Export Development Authority (MPEDA)
presented the status paper on scampi
farming in India. Scampi is cultured in
34,630 ha area in the country. The average
production per hectare ranges from 880
to 1250 kg. He has noted that 62% of
the scampi culture operation is in Andhra
Pradesh. Presently 71 hatcheries are
operating in various states supplying
183 billion scampi seeds to the farmers
in India. The high cost of seed and feed
is a problem facing scampi farming in
India.
In the biology and capture fisheries
session, Jain M. Wagner (Griffith University,
Queensland, Australia) presented
a paper on the implication of translocation
and interbasin water transfers of the
Paratya australiensis species in Western
Australia. E. B. Agasen (Philippines)
presented a paper on the commercially
important species of freshwater prawns
in Luzon and Pena Island of Philippines.
Twelve species of freshwater prawns
were identified, the largest among these
was giant freshwater prawn M. rosenbergii.
P. Das (CIBA, Bhubaneswar) described
the genetic characteristics of the
species of Macrobrachium using RARD
PCR profiling. The lead paper in the
Disease and Health Management session
was by C. V. Mohan (NACA, Bangkok).
He gave an overview of the issues and
responsibilities involved in health management
in aquaculture. Jean Robert
Bonami, a world authority on fish diseases
from France, presented a characterization
of two virus (MrNV and DSV),
pathogenic agents of the White Tail Disease
(WTD) of the giant freshwater
prawn M. rosenbergii. Joannes Sri Widada
(University Montpellier II France) presented
a paper entitled ‘Genome-based
detection methods of MrNV and DSV,
the pathogenic agents of White Tail Disease
(WTD) in M. rosenbergii, possible
use in the study of viral association and
the evaluation of disease severity’. He
suggested that due to its sensitivity and
ease, the use of RT-PCR appeared to be a
versatile method for early diagnosis of
white tail disease which causes a high
mortality of M. rosenbergii. Sahul Hameed
(Abdul Hakeem College, Vellore) discussed
the clinical and histopathological
signs of white tail disease of M. rosenbergii.
In the session on hatchery technology,
David Yesharian and James Tidwell
(Kentucky State University) discussed
the effect of tank colouration on the larval
development of freshwater prawns.
Nani Gopaldas (University of Chitagong,
Bangladesh) reported on the rematuration
of hatchery used wild spawners of M.
rosenbergii in captivity. C. Vasudevappa
(University of Agricultural Sciences,
Bangalore) reported that freshwater cladocerm
(Hoinasp.) can be substituted for
larval rearing in freshwater prawn M. rosenbergii.
In the session on farming technology,
Illan Karplus of Israel presented a paper
touching areas of crucial research to gain
better understanding of the growthregulating
mechanism of M. rosenbergii.
A paper on prawn fish culture in backyard
water berths in Bangladesh was presented
by Kan Mohammed Nurul Islam
(Caritas Fisheries Project, Bangladesh).
Vu N. M. Son (Asian Institute of Technology,
Thailand) presented a paper on
the river culture of giant freshwater
prawns of M. rosenbergii in South Vietnam.
David Yesharian reported the effects
of stocking different grades of prawn
juveniles on production. Effects of different
fertilizers on the production of integrated
rice prawn culture was dealt
with by Davohuygiap (Asian Institute of
Technology, Thailand). Hardayal Singh
(Ludhiana Centre of CIFA) reported record
growth of production of giant freshwater
prawns M. rosenbergii in Haryana.
Debbie Williams (DANIDA project,
Bangladesh) presented the prospects of
giant freshwater prawn farming in Bangladesh.
A farmers–scientists–officials–industrialists
interaction session was held.
More than 100 farmers from different
states of India participated in the interaction
session. Haribabu (College of Fisheries,
Nellore) translated the gist of
presentations in Telugu.
In the award distribution ceremony,
U. K. Viswanatha Raju (Ananda Group
of Companies, Bhimavaram) won the
Pioneer Award for setting up the first
commercial hatchery in the country. His
hatchery was based on the technology
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1398 CURRENT SCIENCE, VOL. 85, NO. 10, 25 NOVEMBER 2003
*A report on the International Conference on
Acoustic Communication by Animals held
during 27–30 July 2003 at University of
Maryland and on the XIX International Bioacoustics
Congress held during 10–15 August
2003 in Brazil.
developed by the Fisheries College, Panangad.
K. Gopala Reddy of Nellore won
the Best Freshwater Prawn Farmer
Award, while ch. Srikanth, Nellore won
the Propagation Award for Scampi. The
Best Young Scientist Award was won by
K. R. Salin for his paper ‘Live transportation
of scampi without water’. The Best
Scampi Exporter Award went to K.
Eravikumar (Five Star Marine Exports
(P) Ltd, Chennai) and the Second-Best
Scampi Exporter Award to M/s Victoria
Marine and Agro Exports Ltd, Chennai.
Outstanding Aquaculture Scientist Award
instituted by Aquaculture Foundation of
India was given to C. Mohanakumaran
Nair (College of Fisheries, Panangad).
Best State Award for Scampi Culture
Propagation was given to the state of
Andhra Pradesh which now has about
one lakh acres under freshwater prawn
farming.
Four scientific sessions were held on
the final day of the symposium. In the
session on nutrition and feeds, the lead
paper on Macrobrachium nutrition, feed
and feeding was presented by Mali
Boonyartpalin, Thailand. She suggested
that a level of 30 to 35% of protein in
diet of freshwater prawns M. rosenbergii
is ideal. Brood stock feed of high level of
18: 2n – 6 and n – 3 HUFA (13 and
15 mg/g DW) has been found to improve
fecundity, egg hatchability and overall
quality of the larvae. Madhumita Mukherjee,
West Bengal reported that feeding
with natural food alone up to 9th day
and artificial food thereafter resulted in
successful production of post larvae of
M. rosenbergii.
In the session on post-harvest technology,
K. A. Devadasan, Central Institute
of Fisheries Technology (CIFT), Kochi
highlighted the salient features of the
post-harvest technology in giant freshwater
prawn. M. K. Mukundan (CIFT,
Kochi) said that chemical contaminants
and antibiotic residues were threats for
scampi raised by aquaculture. However,
he mentioned that microbial quality of
farmed giant freshwater prawns in India
did not exceed tolerance limit. Cadmium,
lead, mercury in ppm were within limits.
It was mentioned that to reduce TPC, antibiotics
were being used, which was
causing problems. Mukundan said that a
farming package based on sanitation and
hygienic safety had to be developed for
ensuring production of good quality giant
freshwater prawns. In the session on
economics and marketing, J. Bojan
(MPEDA) reported that in India there
was a spurt in the freshwater prawn
farming activity in recent years resulting
in production of 30,450 mt from 34,630 ha
in 2002–03. He attributed this mainly to
the availability of water bodies, establishment
of hatcheries, production of low
cost prawn feed and enthusiasm of entrepreneurs.
J. V. H. Dixtulu (Fishing Chimes,
Visakhapatnam) stressed the need for nation-
wide promotion of giant freshwater
prawn farming through survey of sites,
assured aquaculture inputs and technical
support for farming, processing and marketing.
In the session on sustainability
and environment, M. N. Kutty, who presented
the lead paper, said that the annual
expansion rate of freshwater prawn farming
in the world during the decade ending
2001 was estimated as 29% and that
between 1999 and 2001 as high as 48%.
He emphasized the requirement of establishing
sustainable freshwater prawn
farming systems as per the guidelines
formulated by FAO and other agencies in
order to prevent an unexpected collapse
as in the case of shrimp farming.
Michael New, UK made remarks consolidating
the points raised in the symposium
in the plenary session. He was
impressed with the enthusiasm shown for
scampi production in India and its rapidly
expanding output. Regarding hatchery
technology, he suggested the need for
having small seasonal hatcheries on all
farms or for co-operative seasonal hatcheries
that serve a number of small local
farms. Breeding programmes to improve
performance, and possibly the production
of hybrids that exhibit the favourable
characteristics of more than one species,
are desirable. There is also a need to protect
the natural resources in a country
like India where the major cultured species
are indigenous. Conservation of
genetic diversity is critically important.
Everybody agrees that all-male culture of
Macrobrachium is beneficial. This can
be achieved by the administration of substances
derived from the androgenic
gland to induce all-males. The second
possibility would be the production of
all-male progeny through the development
of functional neo-females to be
mated with normal males. Michael New
said that the latter solution could lead to
global dominance by a few major hatcheries
that would control the supplies of superior
stock, an analogous situation to that
prevailing in the poultry industry globally.
The former solution would better protect
the small operators around the globe.
D. D. Nambudiri, College of Fisheries,
Kerala Agricultural University, Panangad
682 506, India
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