Rotifers in shrimp
larviculture
From: Dallas E. Weaver, Ph.D. deweaver@gte.net
To: shrimp@yahoogroups.com
Sent: 31 January 2003
Question:
Interested in finding out the experience in using
live and/or frozen
enriched rotifers for shrimp larval feed? I have been working on
some technology which may allow high and stable production to be
achieved, but with very large economies of scale. With larval fish,
I can cut into my Artemia cost. How about shrimp larvae?
Dallas E. Weaver, Ph.D.
Scientific Hatcheries
5542 Engineer Dr.
Huntington Beach, CA 92649, USA
Tel: 714-890-0138
Fax: 714-890-3778
e-mail : deweaver@gte.net
***************
Comments 1:
With vannamei, shrimp larvae will be very happy to
get rotifers but it may become un-economical after Mysis - PL2 as they will
eat a lot. With enrichment it’s better and it would be a pity not to take
advantage of their filtering characteristics to boost their nutritional
value.
At these stages and when you reach bigger PL 5-6 you can switch to Artemia
biomass, preferably enriched; thus cutting a lot on Artemia cysts but that
will require some changes of practice in your lab.
You can also try frozen or refractance dried DLT Daphnias for the later
stages.
Eric Pinon
e-mail : epinon@ecua.net.ec
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Comments 2:
I cultured rotifers in Iloilo, Philippines for
feeding to Chanos chanos
(milkfish) larvae and tried feeding them to mysis Z3 to M3 P monodon larvae.
After adding to small containers and then observing the gut content under
the microscope I saw no signs that the larvae were eating the rotifers. Also
I didn't see them actually grabbing the rotifers looking in beakers either.
I found that quite surprising given that Z3 monodon will eat just about
anything you put into the tank. Don't know about vannamei larvae though.
e-mail: Bauman.BAL@starband.net
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Comments 3:
It is surprising that Z3 will eat anything. To my
experience I have not come across any Z3 stage larvae feed on Artemia leave
out rotifers. Even at M2/M3 stage only very healthy larvae start eating
Artemia. Rotifers could be tried in PL stage
Chandrasekar
e-mail: aqua@omanfisheries.com
***************
Comments 4:
Once Artemia molt to instar 2 Z 3 monodon cannot hang
on to them and neither can M1-M2. But instar 1 will be readily eaten by Z3
as well as all mysis stages. It 's a little dangerous if you overfeed them
though because the uneaten Artemia will continue to grow and by PL 1 you
will have a lot of big Artemia in the tank. By PL 5 they will disappear but
it makes tank management a little more difficult. But I know people in the
West feed frozen Artemia to all stages of mysis and get good results.
For this reason, I never fed monodon Artemia (18 hour hatch to get
instar 1) until 48 hours after turning to mysis. This way any uneaten
Artemia would be consumed by PL 1. This method produced PL’s that achieved
90% plus survival in grow out.
If your Z3 won't consume newly hatched Artemia
something is wrong and they are weak. I saw them grabbing the Artemia and
hanging on in beakers and it is unmistakable when you look at the gut
content under the microscope. But again, it's a rather moot point because
it's too dangerous if you overfeed them.
But you're right about mysis 1. They get lucky sometimes but have no
"hands" to hang on with. It's like grabbing onto something with
your forearms. But mysis 3 are stronger and can feed on them. But only
instar 1.
Hank
e-mail: Bauman.BAL@starband.net
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Comments 5:
You are right. You can feed frozen Artemia to all
stages of shrimp
larvae. But still I don't think Z3 can feed on live Artemia how fresh or
smaller it can be. It is my experience that even at M1 stage shrimp larvae
rarely feed on Artemia as they just start overcoming the stress of being
head side down. The best results would be to change the algae to larger
diatoms like Skeletonema with some artificial diet. M3 is the ideal stage to
introduce Artemia and again as you mentioned in small
quantities so that Artemia do not eat off all the available algae in the
tanks.
Chandrasekar
e-mail: aqua@omanfisheries.com
***************
Comments 6:
There are so many researches on application of
rotifers in penaeid larvae culture .In Marsupenaeus japonicus and P.
kerathurus Z2 and Z3 (Hirata et al. 1985), in Fenneropenaeus indicus
Z 1 and in P. semisulcatus Z2 (Emerson 1984) are proper stages for
feeding on
rotifers.
Recently one of my students had done a research in this regard. The result
shows in Fennerop. indicus Z3 is the most suitable stage and rotfifer could cut
50% of daily Artemia requirements off.
The quality (weight, carapace length, and salinity test) and survival rate
will decrease if larvae feed on more than 50% of daily Artemia requirement.
Mehdi
Shakouri
e-mail: mehshakouri@yahoo.com
***************
comments 7 :
For Z3 (stocked at 200/lt) P. vannamei larvae it is
standard procedure to feed instarI at 0,5/ml of tank volume. It's better
frozen since the larvae's capacity to catch the prey is still very limited,
but under the microscope you can see they actually ingested them. As they
reach MysisI stage we go to 1/ml, and so on...If you overfeed a tank the
Artemia will grow faster then the larvae and will compete for the nutrients
+ will be a problem at the harvest especially if you count by weighing the
larvae vs. volumetric.
Francois Brenta
e-mail : fbrenta@hotmail.com
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CommEnts 8:
Samocha, T.M., Uziel, N., and Browdy, C.L., 1989. The
effect of feeding two prey organisms, nauplii of Artemia and rotifers
Brachionus plicatilis (Muller) upon survival and growth of larval marine
shrimp Penaeus semisulcatus (de Haan). Aquaculture 77:11-19.
Craig L. Browdy
President - World Aquaculture Society
Marine Resources Research Institute
South Carolina Department of Natural Resources
217 Ft. Johnson Rd. (P.O. Box 12559)
Charleston, SC 29422, USA
Phone: 843-953-9840
FAX: 425-944-2449
Email: browdycl@musc.edu
***************
Comments 9:
I have no doubt feeding frozen Artemia to Zoea. Hank
is very sure about feeding live Artemia (Instar 1) to Zoea. However this
subject is not worth debating since every one is concerned about costs. It
is safe and cost effective if Artemia is fed from late M3 through PL stage.
Chandrasekar
e-mail: aqua@omanfisheries.com
***************
Comments 10:
It is probably not economical to use rotifers in
shrimp larviculture. Maybe during severe shortages of Artemia cysts, but
even then you would need the technology for rotifer culture implemented at
the hatchery... . From a technical point of view, the use of rotifers has
some interesting advantages. Small-sized rotifers can be fed in the zoea 2
stage facilitating the early uptake of animal protein and the rotifer's
digestive enzymes. In L. vannamei this resulted in an increased larval
development, while a prolonged administration till PL5 (combined with
Artemia) increased PL dry weights (1). Additionally, the use of enriched
rotifers offers a way to deliver special nutrients or prophylactics to early
larval shrimp stages, e.g. as used for lipid research (2).
(1) Naessens, E, Cobo, ML, Van Hauwaert, A., Van Horenbeeck, M. and
Sorgeloos, P. (1995) Improvement of white shrimp Penaeus vannamei production
through feeding strategies based on live and formulated feed. Memorias II
Congreso Ecuatoriano de Acuicultura, Guayaquil, 20-25 October 1993, p
101-108.
(2) Wouters, R., Van Hauwaert, A., Naessens, E., Ramos, X., Pedrazzoli, A.
and Lavens P. (1997) The effect of dietary n-3 HUFA and 22:6n-3/20:5n-3
ratio on white shrimp larvae and postlarvae. Aquaculture International 5,
113-126.
Of course, we still have artificial diets to partly replace Artemia.
Roeland Wouters
e-mail: r.wouters@inve.be