MEDICINE FOR PL TRANSPORT
From: Freddrick Poh fredpoh@starhub.net.sg
To: shrimp@yahoogroups.com
Sent: 7 March 2003
I have a problem in transporting vannamei PL in the
bags, the animal eat each other when they molt in the bag. Is there any way
or medicine to rectify this problem, that say can prevent the animals from
molting in the bag.
Freddrick
e-mail: fredpoh@starhub.net.sg
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COMMENTS 1:
If the shrimp eat each other it is probably more
because of getting hungry than a disease. Then a drug would not be
advisable.
I recommend you place some Artemia nauplii in the bag too when shipping;
thus the Artemia will be eaten first before the shrimp start to eat each
other. Making a few tests, you will find which quantity is appropriate for
the length of transportation. Mind about the oxygen too as Artemia breathe
also.
Eric Pinon
e-mail: epinon@ecua.net.ec
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COMMENTS 2:
This discussion suddenly rings a bell to us. Lately,
we have been acquiring vannamei fry from hatchery located quite far away
from our facility. From hatchery to our farm would take a total of 12 hours
journey. Truck for 6 hours, 2 hours flight then another 4 hours journey to
our site.
Upon arrival, we usually do a random check on the numbers by counting a
couple of bags. Everytime there's fewer than reported by the hatchery. It's
a quite substantial amount (25% less). Just wonder whether it's because of
cannibalism ? With P. monodon, we do not have any problem (the travel time
is just around 5 hours).
Tommy Chandra
MAKARA Bumi Satya - North Bali, Indonesia
e-mail: tchandra@bhinneka.com
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COMMENTS 3:
I won't suggest that hatcheries will cheat on this
account. It is a genuine problem even after taking so many things into
account, some thing go wrong. My experience in India and Iran was always
mixed as some times we get more than 85% survival and some times around 70%.
To confuse further there are reports in favour as well as against feeding
post larvae with feed prior to packing and adding Artemia to the transport
bags.
You feed them prior to packing and add Artemia, then at the end of journey
what you get is water not clear and poor survival. Again the same result
when you do not feed them due to cannibalism.
However follow this procedure and try some minor changes:
Insist the packing water at 20°C.
Ask the hatchery to reduce the temperature gradually
Ask them to add some algae to the packing water
Ask the hatchery to stop feeding two hours before packing
Add few Artemia to the packing water
This way you can marginally increase the survival rates but not
substantially.
M.Chandrasekar
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COMMENTS
4:
The technical inputs you are hearing from various
list members are certainly valid. But there are other considerations. And
these other considerations are the culprit in these situations more often
than the technical ones. 1, Farm technicians are famous for under counting
hatcheries. The main reason is to get "higher" survival, or 2, you
may be dealing with a new hatchery who is dealing with a broker who is
undercounting. Also PL 10-12 vannamei are generally much smaller and harder
to see than the standard 13 mm monodon PL. Twelve hours is not a long
shipment, especially for vannamei. (at 12 -15K/liter) Cannibalism
usually starts after 17-20 hours even when packed
at 20°C. I would go to the hatchery and watch them pack. Do random
counts there before shipping.
Hank
e-mail: Bauman.BAL@starband.net
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COMMENTS 5:
Transportation of vannamei over 12 hours is usually
not a problem but I have no experience to compare with monodon.You certainly
have to be careful with density, use some carbon activated in the bags (in
granulated) and maybe try with some live nauplii as food. The other
possibility is that your counting method differs with the hatchery
counting method.
Eric Pinon
e-mail: epinon@ecua.net.ec
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COMMENTS 6:
Lipids is a form of slow release energy. There
has been a concept used by only a handful of hatcheries called lipid loading
in which several days before shipment from the hatchery, you start to load
the PL's up with lipids, particularly DHA and EPA. This can be
monitored by standard red oil stain methods as compared to PL's not fed high
lipid diets.
Stored energy tempers the various stresses caused by the movement
of animals and the protocols by which the hatcheries prepare the
animals for movement. Think about it, feeding is terminated prior to
packing, the temperature is lowered to slow down metabolism, the salinity is
sometimes adjusted closer to pond conditions, packing is done in high
density, etc., then at farm the animals go into totally different water
condition, the feed is not of hatchery quality, temperature is whatever it
will be, etc.). Cannibalism is just a feeding reaction driven by nutrient
deficiencies.
Some companies have established farm side acclimation raceways in which they
can extend the monitoring time and condense the feeding with better quality
of diets for a few days upon arrival from the
hatchery and prior to putting the animals into the ponds.
Lipid loading can be implemented (depending on the species) with
very high fat diets, but the type of fats should be either fish oils
or ingredients that are exceptionally high in EPA and DHA. Most
hatchery diet lipid levels are in the range of 9-13% overall fat and most of
this is contributed by fish oil. The upper limit is somewhat dictated
by the processing methods since getting any particle to bind and stablize
gets more difficult as the level of fats (in the form of oil) increase.
Lipid loading diets will be in the range of 18-22% over all fat and is
usually fed as a replacement for one or two of the daily feedings from what
is normally fed for the last 4-5 days of the hatchery cycle prior to
shipment.
Lipid loading can also be accomplished by addition of high fat algaes
into the hatchery diets intended to boost the lipids and/or for the farm
acclimation diets. You can contact us off list for such algae options.
At farm side, the shipment protocols are reversed with acclimation. If there
are acclimation raceways, animals can be monitored and fed better quality
diets for a week before the animals are released into the pond. Note
that nearly 40% of overall pond mortality occurs within the first 30-40 days
of life. How much of this is due to proper acclimation or fitness of
the animal at the time of release has not been proven but if you are finding
evidence of movement stress (canibalism, weak animals, etc.) then pond
release immediately will certainly not help the survival.
Doesn't take a rocket scientist to figure that marginal improvements in pond
survival more than covers the cost of proper preparation of the animals
prior to release. That preparation is largely nutritional and
acclimation if the animals are healthy to begin with.
Leland Lai
Aquafauna Bio-Marine, Inc.
e-mail: lelandlai@aquafauna.com
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COMMENTS 7:
All my counts on vannamei shipped by air 24 hrs at
about 20°C have
agreed with the shippers within about 5% (both ways, short and high).
There are usually, but not always, live Artemia in the bags.
Dallas E. Weaver
e-mail: deweaver@gte.net
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COMMENTS 8:
You should also look at the actual count made at the
hatchery. Is it volumetric or weighted? A 25% error margin is not unusual on
volumetric counts especially for larger size animals. Have you actually
observed mortalities in the bags? If you have a microscope you should also
look at the pleopods, periopods and uropods, you'll see signs of canibalism
there (if there's any). If you have doubts of the packaging procedure prior
to shipping here are some basics: 400 000 Artemias (instar I) per bag, for
PL10 should have about 10 000 pls per bag (for a 12 hours trip, you can
lower the temperature for transportation to as much as 18°C, but 20 to 22
will do it.
e-mail: fbrenta@hotmail.com
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COMMENTS
9:
Packing
PL's in bags should be done accordingly with the PL's age, density (#
PL's/Lt ), Temperature, transport distance or time length, among other
factors.
If the PL’s are molting, probably they are being
exposed to stress factors such as rough handling, drastic temperature
change, overcrowding, etc. You can prevent molting and eating each other
reducing their metabolism by. Lowering the temperature, providing live
Artemia, helping the water not to foul adding some charcoal and adding
oxygen will help them as PL’s and Artemia breathe.
Jose Manzo
e-mail: p2manzo@yahoo.com
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COMMENTS 10:
I feed the dried crustacean, "Cyclopeeze"
to F. indicus PL's prior to
packing to reduce cannibalism. This is psychologically very satisfying as
you see the red colour quickly spread through the hepatopancreas and down
the gut. I have not evaluated the effect over the long shipment periods
mentioned.
Laurence Evans
e-mail: Laurence@amatikulu.co.za