The
WorldFish Center Quarterly
Vol. 26,
No. 2 (April June 2003)
Age-
or length-based methods of grwoth estimation.
What drives the choice?
G.M. Pilling and A.S. Halls
Abstract
* Please refer
to the full text article in the PDF
View
Article (PDF 473 KB)
Pawpaw
seed as fertility control agent on Nile tilapia
S.B. Ekanem and
T.E. Okoronkwo
Abstract
To
fi nd out if pawpaw (Carica papaya) seeds can
induce sterility in male Nile tilapia (Oreochromis
niloticus) and to determine if sterility so induced
is reversible or otherwise, mature male tilapia
of mean weight 40 g were treated for 30 days with
a low dose (4.9 g/kg/day) and a high dose (9.8
g/kg/day) of ground pawpaw seeds incorporated
into their feed. Fish of similar sizes in the
control experiment were fed with feed that did
not contain pawpaw seed. The pawpaw seeds induced
permanent sterility in the fi sh that received
the high dose, while sterility in the low dose
treatment was reversible. Fish in the control
experiment spawned two weeks into the experiment
and again in the fifth week. Fish in the low dose
treatment spawned three weeks after the treatment
had been discontinued. Histological sections of
the testes showed that pawpaw seeds produced swollen
nuclei in the low dose treatment and disintegrated
cells in the high dose treatment. The study showed
that pawpaw seeds, which are easy to obtain, can
be incorporated into fi sh feeds and used by farmers
to control prolific breeding of Nile tilapia.
View
Article (PDF 66 KB)
Fisheries
production in Asia: Its role in food security
and nutrition
P.S. Choo and M.J.
Williams
Abstract
Prediction
of the worsening condition of fi sheries stocks
worldwide and of aquatic ecosystems in crisis,
together with the uncertainty on whether the emphasis
given to intensive aquaculture production (which
is still heavily reliant on fish meal and fish
oil) is sustainable and is able to contribute
to net growth in fisheries production, have been
vigorously discussed and well documented in recent
years. These challenges were recognized by the
World Summit on Sustainable Development in 2002.
The future of fi sheries and their sustainability
will have great consequences in Asia, where large
populations live in riparian and coastal states
and are heavily dependent on fisheries and its
products for food and for livelihoods. Asian countries
produce almost 50 per cent of the worlds
total capture fi sheries production and about
90 per cent of the worlds aquaculture production.
Coastal and riparian states in Asia rely heavily
on fi sh as a source of food, and statistics from
FAO indicated that per caput consumption of fish
from the East and Southeast Asian countries (24.0
kg), and China (24.7 kg) surpassed the global
average of 15.8 kg. Some Asian countries are also
important seafood exporting countries, with Thailand,
China, China-Taiwan, Indonesia and the Republic
of Korea ranking among the top ten world exporters
of seafood.
Fish
and other living aquatic animals have often been
classifi ed as a good source of protein, vitamins
and minerals. In recent years, fi sh has been
acknowledged as a functional food and has important
roles in the prevention and management of heart
disorders, neurological diseases and mood swings.
Important products such as fish leather, squalene,
chitosan, eicosapantaenoic acid (EPA), and docosahexaenoic
acid (DHA) are also obtained from fish and fisheries
products.
This
paper reviews the status and some management issues
of fisheries production in Asia, as well as the
supply and demand situation. Its food security
and nutritional roles and opportunities for value
addition are also discussed.
View
Article (PDF 51 KB)
Length-weight
relationship of some deep sea fishes inhabiting
the continental slope beyond 250m depth along
the west coast of India
J. Thomas, S. Venu
and B.M. Kurup
Abstract
The
lengthweight relationships of 22 species
of deep-sea fi shes inhabiting the continental
slopes beyond 250 m depth along the West Coast
of India are presented. The parameters a
and b of the equation W=a Lb
were estimated. The fish samples were collected
from trawl surveys during 1999 to 2001 on board
the FORV Sagar Sampada at a depth range of 250
to 600 m in the area between 7°N and 20°N
latitude. The value of b ranged from 1.94
to 3.36.
View
Article (PDF 58 KB)
Incidence
of human pathogenic bacteria in shrimp feeds -
A study from India
R.P. Raghavan
Abstract
The incidence of various human pathogenic bacteria
in commercially available and home-made shrimp
feeds used on some farms in India was analyzed.
The Total Heterotrophic Bacteria in the commercial
feed samples ranged between 103105 cfu g-1
and those in the farm-made feeds between 106-107
cfu g-1. No bacteria of significance to human
health were found to be associated with any of
the commercial feed samples analyzed, while farm-made
feeds analyzed during the study showed a high
incidence of various human pathogens such as Vibrio
parahaemolyticus, V. cholerae, Escherichia coli
and Staphylococcus aureus. Possible modes
of contamination in feeds and ways to prevent
them are discussed.
View
Article (PDF 30 KB)
The
cost of action: CRM investmentin the Phillipines
A.M. Salamanca
Abstract
Knowing
the cost of investment in coastal resources management
(CRM) is important especially in understanding
the cost of undertaking one and ascertaining whether
the outcomes are worth the money spent. In the
Philippines, various CRM projects have already
been initiated and no studies have tried to account
for the total level of investment. This paper
provides an estimate of money spent or invested
on CRM in the Philippines and examines the investment
per km2 of coral reefs.
View
Article (PDF 44 KB)
INGA
Article
Stock evaluation and development of a breeding
program for common carp (Cyprinus carpio)
in Karnataka, India: progress of a research project
Y. Basavaraju,
D.J. Penman and G.C. Mair
Abstract
Common
carp (Cyprinus carpio) is the single most
important species for aquaculture in the state
of Karnataka, India, where it is generally grown
in polyculture with Indian major carps. Precocious
maturation and unwanted reproduction in the species
have been identifi ed as constraints to increase
production in aquaculture and culture-based fi
sheries in Karnataka state. Stocks of C. carpio
obtained from Hungary (Amur and P3), Indonesia
(Rajdanu) and Vietnam (SV) are being assessed
alongside two local stocks (L-BRP and L-FRS) in
a series of culture performance trials with the
objective of setting up a base population for
selective breeding. The paper presents progress
of research being undertaken at the Fisheries
Research Station, University of Agricultural Sciences,
Bangalore, India.
View
Article (PDF 55 KB)
|