7145 ‎(2)‎

• UCREFRP Catalog Number: 7145
• Author: Inslee, T. D.
• Title: Spawning of Razorback Suckers
• USFW Year: 1981.
• Copyright Material: NO

• ~~ l~r~
Egg hatching in the six-foot circular tank that the water was 22 inches
deep proved less than satisfactory. There was not enough flow through the
rock bed, which resulted in a putrid area where eggs were incubating.
Another prot~lem in the first trial was the heavy growth of fungus that
probably further reduced the flow of water through the rocks. The lowering
of the water with a six inch standpipe helped to alleviate the problem. The
non-aeration of eggs was not encountered in the second trial with the lowered
i
standpipe.' The problem of fungus was still present. The hatching success of
viable eggs could not be measuzed due to the unknown total number of eggs.
Observations of and counts of viable versus non-viable eggs gave indications
that the hatching success of viable eggs in the second test was as high as
could be expected. The circular tank hatching is one method that is recom-
mended even though fungal growths will be hard to control. Another disad-
vantage is not being able to determine what is happening and the culturist
has very little control over the eggs while in the tank.
The tray suspended in a tank hatching attempt gave indications t~1at
this may be a method that could be utilized. Water exchange and aeration
was not what would be desired. I,~ater flows piled some of the eggs. Fungus
problems were encountered and will be difficult to control utilizing this
method. The percentage of viable eggs was low that was utilized in this
test. This technique needs further testing with air stones added to in-
crease aeration of water.
The hatching method that gave the best results was the Heath incubator.
The one drawback was the heavy fungal infestation that developed on the 3rd,
4th and 5th day. The fry go through the screen and can be removed from the
trays through the clean-out hole. Even though fungus may be controlled in
the future, the lar a percentage of bad eggs will cause problems of hatching
eggs regardless of the method used. The non-fertile eggs start to break down
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