Why the high temperature?
Dallas Weaver, Ph.D.
deweaver at gte.net
Mon May 14 09:59:16 EST 2001
I previously raised the question of why researchers are using such
high temperatures (28.5 C) when the animals do very well and the
human working conditions are much better at 25 C. I ended up
with a significant response indicating a lot of agreement that lower
temperatures are preferred. A few people brought up the standards
problem and the fact that some more work would be required to
develop a full set of development standards for lower temperatures.
The one argument in favor of the higher temperature was the claim
that you can get faster egg to egg turnover time at the higher
temperature. Under conditions of perfect water quality, perfect feed
(live feeds being the best) and low densities, the maximum growth
rate temperature will usually give the shortest egg to egg time on
non-seasonal spawners. This is not true for all species of fish,
where many species must go through a cool cycle before
Has anyone proved that zebra fish have the shortest egg to egg
times at 28.5 C, or have we just assumed that this is true????
What are the real "egg to egg" times most laboratories are
How important is having the minimum time???
My reasoning for asking these questions stems from the possibility
that we could shorten these times with better feeds and water
quality. I am thinking of live feeds produced under SPF (specific
pathogen free) conditions and distributed to the laboratories. If it
looks like the potential market is large enough for a "clean" live
feed, we could do the R&D necessary to develop the product. Live
feeds would have the additional advantage of not polluting the water
until eaten and only require once per day feeding while achieving
very fast growth rates.
If you respond to the questions about egg to egg time, please
include the number of mature zebras produced per year. This
would provide an idea of the feed requirements and the potential
market for live feed.
PS: For the researchers who don't know who we are. Scientific
Hatcheries is a producer of live aquatic animals, most of which is
live fish, which are used to feed other fish. We adjust the fatty acid
distribution of our product to match the requirements of our
customers (marine fish require high levels of omega 3 fatty acids --
DHA, EPA). Our customers, for the 20 million live fish per year
that we produce, range from the pet hobby trade to major public
aquariums and research laboratories working with animals that
prefer/require live feeds. There are a lot of aquatic animals, such
as tuna and squid species, who use movement as a key to feeding
We also provide zebra danios and embryos to researchers, as a
sideline to production of about 50,000 to 100,000 zebra danios for
the feeder and ornamental markets.
More information about the Zbrafish