ROTIFERS IN SHRIMP LARVAL REARING
From: padlab padlab@yahoo.com
To: shrimp@yahoogroups.com
Sent: 6 August 2004
QUESTION:
Can anyone share their experience in using rotifers
or copepods as
Artemia replacement in a commercial shrimp hatchery?
Ramraj
e-mail: padlab@yahoo.com
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COMMENTS 1:
I do know that China has used a lot of rotifers in
their larval culture. Probably the best source of information.
I have used rotifers with vannamei and they love them. Even near
adult shrimp will come up into the water column and use their legs to
filter feed the rotifers from the water. PL's also do very well on
rotifer, but I was still using Artemia at that time of these
experiments as my rotifer supply did not have the required reliability.
I have now substituted rotifers for Artemia in my larval fish culture
with a new rotifer system design that does appear to have the required
continuous production reliability and stability. It is still in the
development phase of R&D, but I am averaging about 8 kg wet wt of
rotifers per day. However, I am no longer doing vannamei.
The economics of rotifer production has very significant economies of
scale with larger systems being more economical. Labour cost is
almost independent of production levels. I am using a yeast + other
stuff type diet in a continuous production system with L type rotifers.
It looks like large systems will beat the cost of live Artemia
nauplii.
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@surfcity.net
URL: http://www.ScientificHatcheries.com
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COMMENTS 2:
CENAIM (Ecuador) did a considerable amount of work
with rotifers and larval rearing; they would probably be a good source of
information.
David Griffith
e-mail: dgriffith@seafarmsgroup.com
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COMMENTS 3:
The Kuwait Institute of Scientific Research (KSIR)
did some interesting studies on the consumption of P. semisulcatus by larval
stage of rotifers in the early 1980's. Browdy and Samocha indicated that the
growth of penaeid shrimp larvae on a rotifer diet was inferior to that of
Artemia. Emerson in South Africa also indicated that the energetics of a
rotifer diet vs Artemia was low. But these studies were done before
the enrichment diets hit the market.
Several studies we did with Algamac-2000 enrichment diet actually showed a
superior uptake of DHA by rotifers compared to Artemia. It appears the
Artemia retroconvert DHA once it reaches a certain level in their system.
Certainly the success of the more extensive penaeid larvae rearing systems
using rotifers in areas where Artemia AND enrichment diets are prohibitively
expensive or unavailable would indicate that they are an alternative worth
considering.
As Dallas pointed out, it will all come down to whether you can produce the
quantity of rotifers you need more cost effectively than the price of
Artemia.
e-mail: pboeing@dc.rr.com
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COMMENTS 4:
I cultured Brachionus (sp?) for culturing milkfish in
the Philippines and tried feeding them to mysis stage monodon. I watched
them in the beaker and looked at gut content under the microscope. I saw no
evidence that they were eating any at all.
Hank Bauman
e-mail: Bauman.BAL@starband.net
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COMMENTS 5:
Regarding rotifer feeding to monodon post larvae, the
best option would be to feed differently enriched rotifers for different
stages.
Naturally DHA-fortified Isochrysis cell autolysates-enriched rotifers for
mysis; crab egg suspension-enriched rotifers for early postlarvae ;
minced-clam liquor-enriched rotifers for late post larvae.
Sodium nifurstyrenate-bath rinsing is a must before feeding.
This manipulation is never a total supplementation for Artemia. A 50 %
substitution is possible.
The crucial factor is the cheap production of rotifers outdoors with outdoor
grown Chlorella fertilised with commercial fertilisers and sterilised clam
paste or sterilised poultry intestine paste to reduce production cost. Yeast
is sure an additional feed in the culture process.
Dr.M.Rufus Kitto
State of Kuwait.
e-mail: ashakitto@yahoo.co.uk
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COMMENTS 6:
I would not recommend poultry by-product use in
shrimp farming at this stage.
Chicken are commonly fed with the so called "growth promotors"
which are nothing else than antibiotics at low doses and other kind of magic
bullets to control their health. This is not to think of adequate veterinary
and therapeutic treatments the chickens may also have received.
It could compromise you shrimp production (food safety) to use animal
by-products, in particular products and feed from the poultry industry.
Eric Pinon
e-mail: epinon@serviceaqua.com
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COMMENTS 7:
Much of the northern marine bottom and flat fish
incorporate rotifers in the larval rearing due to the small size for
ingestion. For shrimp, Artemia is usually introduced in the mysis
stage but most species can survive on rotifers from earlier stages.
In marine culture, as Dr. Kitto and others suggest, rotifers is not a
perfect diet in and of itself and the research definitely indicates
enrichment of some kind makes the difference as to the nutritional value of
this live food, especially for marine organisms.
There are, as indicated by Dallas, non-living substitutes (algae) that can
replace the live algae commonly used for rotifer culture. Some of these are
commercially available and can replace all live algae for
rotifer culture. Reed, Aquafauna, Pacific Trading (Japan), to name a
few have such alternatives. Cost is the issue and some are available
for under US$30.00 per equivalent dry weight basis. Compare this to the cost
for culturing live algae at between $60-+$100/kg on a dry weight basis.
There are also a wide number of choices of enrichments from Super Selco,
fish emulsions to heterotrophic algae like Schizochytrium (AlgaMac) and
Crypthecodinium (AquaGrow). In the end, users will gravitate to the
simplest and least cost products to use and those which are easy to ship and
store.
Leland Lai
Aquafauna Bio-Marine, Inc.
e-mail: lelandlai@aquafauna.com
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COMMENTS 8:
Here are a couple of items from my files on systems
for culturing rotifers:
1. In this study, a feasibility study was performed on a recirculating
system for mass culturing rotifers. With a culture volume of 750
liters, it was tested at stocking densities of 3,000, 5,000 and 7,000
rotifers per milliliter. At all densities, it produced 2.2 billion
rotifers a day for three weeks. Protein skimmers, ozone and a submerged
biofilter maintained excellent water quality. Microbial counts were
stable. For the first year, compared to a commercial batch culture
system, capital costs were reduced by 46%; labor costs, by 65%; and feed
costs, by 21%.
Source: Electronical Larviculture Newsletter. Technical and economical
feasibility of a rotifer recirculation system. G. Suantika (gsuantika@yahoo.com),
P. Dhert, E. Sweetman, E. O'Brien and P. Sorgeloos (Laboratory of
Aquaculture and Artemia Reference Center, Ghent University, Rozier 44,
B-9000, Gent, Belgium). Issue 185, November 1, 2003.
2. Reed Mariculture offers free plans for a high-density rotifer culture
system. Called the Instant Algae Rotifer System, it can easily be put
together from parts you already have or can get from a local supplier.
The system replaces low-density batch production in large growout tanks with
continuous production in small, high-density tanks. It’s a
low-maintenance design that only requires a few minutes of maintenance a
day. The documentation and diagram for the system are available at http://www.rotifer.com.
Features:
-Produces more than 500 million rotifers every day from a 500-liter tank
- Uses less than 10% of the space required for batch systems
- Requires less than 15 minutes of maintenance a day
- Easy to understand, build and operate
- Scalable (from 50 to 5,000 liters)
- Inexpensive (feed cost = 8 to 11 cents per million rotifers)
- Equipment cost of less than $1,000
Information: Randy Reed, Reed Mariculture, Inc., 511 Palmiar Avenue, Suite
C, Santa Jose, CA 95128 USA (phone 408-288-8121, fax 408-884-2322, email randy@seafarm.com,
webpage http://www.instant-algae.com).
Source: Dave Conley¹s Aquaculture Newsclips (dave.conley@sympatico.ca).
New rotifer bioreactor system. Item #9. November 10, 2002.
Bob Rosenberry
Editor/Publisher
Shrimp News International
10845 Scripps Ranch Boulevard, #4
San Diego, CA 92131 USA
Phone 858-271-6354
Fax 858-271-0324
Email bob@shrimpnews.com
Webpage http://www.shrimpnews.com
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COMMENTS 9:
Relative to the discussion on rotifers as a
replacement for "Artemia", I
just checked to see if the following manual (1991), was still in print, and
it is:
"Rotifer and Microalgae Culture Systems"
This 364-page (216 x 280 mm) manual, edited by Wendy Fulks and Kevan Main,
at the time employees of The Oceanic Institute in Hawaii, is the proceedings
of a United States/Asia workshop held in January 1991. The workshop
focused on the techniques and hardware used to culture rotifers and
microalgae, important feeds for developing shrimp larvae. The indexed
proceedings summarizes the findings of the workshop. The introduction
furnishes background information on the design of microalgae and rotifer
culture systems, emphasizing ways to improve reliability and reduce
operating costs. The next section contains 22 papers describing production
techniques in the United States, Japan, the People's Republic of China, the
Republic of Korea,
Thailand, Singapore and Taiwan. The final section outlines the
information exchanged in the discussion groups. Appendices contain the
names and addresses of workshop participants. It sells for $85.00 (reference
#B-ROTI-MCS).
Information: Thomas Sawtell, Argent Chemical Laboratories, Inc., Argent
Laboratories Press, 8702 152nd Avenue, N.E. , Redmond, WA 98052
USA (phone 425-885-3777, fax 425-885-2112, webpage www.argent-labs.com).
Bob Rosenberry
Editor/Publisher
Shrimp News International
10845 Scripps Ranch Boulevard, #4
San Diego, CA 92131 USA
Phone 858-271-6354
Fax 858-271-0324
Email bob@shrimpnews.com
Webpage http://www.shrimpnews.com