Hatchfry encapsulation I

Dallas Weaver, Ph.D. deweaver at gte.net
Mon Aug 11 09:43:09 EST 2003


Christina and others,

When thinking about using various non-living diets on your larval fish, 
you should keep in mind the world wide billion dollar aquaculture 
business of producing commercial larval fish and shrimp. With this 
business spending several hundred million dollars per year on larval 
diets, their experience may be relevant.   

I don't know of any commercial hatchery that has gone to zero live 
feeds for animals with small larval stages.  Dry/prepared feeds are only 
used to supplement live feeds, not replace live feeds.  For example, 
when the price of artemia cysts increases, the hatcheries increase the 
amount of dry feeds to save money, while decreasing the performance 
of their animals.  

As zebra fish researchers are not producing billions of animals, the 
actual cost of the feed is a minor fraction of the total cost of the 
research. Under these conditions, researchers should just forget about 
dry/prepared larval feeds and just use live feeds for the larval stages.  

The performance difference between live and dry/prepared is very 
significant.  When the aquatic feed industry can produce a 
dry/prepared diet that can take a zebra larva from "swim-up -- first 
feeding" to large enough to eat 48 hr artemia napulii in 3 to 4 days, I 
will consider switching from rotifer/paramecia feeds.  When they do 
develop such a dry feed, you will see the price of artemia cysts fall to 
the historical value of < 10$/lb.  

I have talked to researchers who spend 10 days or more on this swim-
up stage and that means 6+ days of lost research effort and, more 
importantly, a fish that was nutritionally stressed at a young age, which 
may impact later research and breeding.  

The only real larval feed issues relevant to zebra researchers revolve 
around how to produce or purchase your supply of live feeds and how 
to enrich those feeds to get the proper nutrition.   I have several 
customers who just buy a weekly supply of rotifers and then feed those 
live rotifers some instant algae to enrich them before feeding to the 
larval zebra fish.  

Dallas

PS: With live feeds all the way, you can go from egg to egg in 47 days
with this fish.  You have to ask, what would that do to your research
cost?


in article bg9of1$389$1 at mercury.hgmp.mrc.ac.uk, Christina 
Quasarano at
ceq at bu.edu wrote on 7/30/03 5:38 PM:

> Hello all!
> 
> It has been suggested to me that I try the hatchfry encapsulation I
> powder as a food source for our larvae.  Have any of you heard of
> this product or tried it before?  If so, could you give me your
> ideas/thoughts/feelings about how well/poorly it proved to be. 
> Thank you!  
> 
> Sincerely, Christina Q
> 
> ***************************************
> Christina Quasarano
> Lab Manager <}}}><
> Chemical Hygiene Officer
> Lab of Sleep Physiology
> Department of Anatomy and Neurobiology
> Phone # (617)638-4187
> ---
> 





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