SHRIMP PL-QUALITY
From : globy10@yahoo.com
To: shrimp@egroups.com
Sent: 21 January 2001
QUESTION:
Any references (in literature, own experience,
previous research)
related to influence of PL-quality (P. monodon) on survival, yield &
growth?
I'm working on a MSc thesis; subject : influence and prediction of PL-
quality on growth & survival of P. monodon in grow-out ponds.
I'm looking for references in literature to substructure my
statistical data processing.
Furthermore, can anybody pass me a reference related to an article
with the Watchana Sunthorn method? I used this method to qualify my
PL-quality but I want a solid reference.
Bbruno Decock
globy10@yahoo.com
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COMMENTS 1 :
A short summary of the Watchana Sunthorn. It is a
test to check PL quality and is based on following criteria : swimming
behavior, Uropods (closed/open), Antenna (closed/open), MGR (more than 4 and
contamination with Zoothamnium combined with a stress-test. Based on the
results you calculate a score. If this score is more than 80 PL are axpected
to be of good quality (we could indeed relate this test to performance
during transport and have significant results for performance during
grow-out. Only problem is that our number of replicates is too low).
We got this test from Thailand via INVE Asia. Other references would be
welcome though.
Peter
E-mail: roblescarmen@hotmail.com
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COMMENTS 2 :
I have checked PL quality before stocking for
almost two years. I believe it is very important and also directly affecting
the growth and survival, but it is also very important which parameters you
are going to test. I don't think you can find many published papers
about it.
Dr. Farshad Shishehchian
Ph.D. Aquatic Ecology- Shrimp Culture Pond Management
Technical Manager
J.W Farm
Malaysia
E-mail: farshadshrimp@hotmail.com
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COMMENTS 3 :
It's indeed very important which factors you consider
to use in your multiple regression model. During my 4-month fieldwork in
Vietnam, I used Watchana Sunthorn & stress test (formol & deionized
water) to qualify the PL-quality. From my own experience in the field I
noticed that PL-quality has an influence the first week of the grow-out;
during culture it was obvious that management had a bigger influence. So I
use 2 subdata sets: PL-quality & management. I defined management by
location (coast, rice-field), culture method, average salinity, pond bottom
characteristics ( pH, N , P & organic matter). As for my dependent
variables I use survival, yield & final growth (= growth at harvest)
In accordance with my promoter Prof Sorgeloos, we did a tagging experiment
to see the influence of quality on survival & growth during the first
weeks. Because evaluating this in grow-out ponds was too difficult, we did
this small scale tagging experiment.
Bruno Decock
globy10@yahoo.com