PENAEUS MONODON PL BEHAVIOUR IN PONDS

From: tchandra@bhinneka.com
To: shrimp@yahoogroups.com
Sent: 24 August 2001

Question:

We are culturing P. monodon in intensive ponds at our facility.
In almost every time about 10 days to 2 weeks after we introduce the PL’s into our ponds, we usually see the fry move in large groups (convoy) along the banks round and round the whole pond. This would keep on going for several days to a week before they disappear. I have been wondering about this behavior. To most shrimp farmers, it is just a usual phenomenon. I would like to know what should we interprete from this kind of behavior. Is it because of the stress, or any particular reason ?
We have also found that in some occasion this behavior was not observed.
 
Tommy Chandra
North Bali - Indonesia

e-mail: tchandra@bhinneka.com

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COMMENTS 1 :

It is most of the time normal and it very much depends on your pond preparation if your ponds have a lot of natural diet (plankton and benthos) you may not see this behavior. During the first weeks of culture for P. monodon, shrimp has more swimming behavior and are less benthic.

Dr. Farshad Shishehchian
Ph.D. Aquatic Ecology- Shrimp Culture Pond Management
General Manager
Progressive Impact Aquaculture Sdn. Bhd.
Malaysia

e-mail: farshadshrimp@hotmail.com

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COMMENTS 2 :

We observe similar behavior which we call “roaming” in a few newly
stocked ponds.
Roaming is not only easily observed  but is also more pronounced  in
ponds having higher transparencies.
We presume that roaming is an indication of shrimps under stress due to some factor beyond their comfort range. We are wary of roaming and like the shrimps to disappear faster.
We have also observed that those ponds where roaming goes on for many days are more prone to disease outbreaks.
Every time we observe roaming we run the aerators and the same appears to help, that is reduce roaming.

Ajitsinha

e-mail: pancham@bom3.vsnl.net.in

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COMMENTS 3 :

From further observation, we noticed that this particularly happen around 1 to 3 pm in the afternoon when the water temperature is at its peak. When we have incoming water, they all seemed to swim towards the incoming water. I assumed one of the possible reasons is high water temperature during midday (stress). This behavior is now happening in 4 ponds at our facility where all the four banks and pond bottom have been cement plastered. Lack of natural feed might likely be one of the reasons judging from the condition of the ponds where there's no contact with soil.

Tommy Chandra - North Bali, Indonesia

e-mail: tchandra@bhinneka.com

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