7145 ‎(2)‎

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

A
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sweeping was evident until March i~, at th~~ time of the preparation of this
report.
The C series ponds proved to be a poor choice for spawning ponds. The
ponds were new, with no vegetation on the dikes to reduce erosion. Any
strong wind caused the water to become turbid c,~hich resulted in silt on the
rock spawning beds. Also the water action caused a general erosion of the
dikes over parts of the rocks. Should older ponds have been available for
use with dikes settled and stabilized, the problem of settelable solids would
have been lessened. The strong winds during this time of year will cause some
dike erosion and siltation in all ponds, thus may limit the success of pond
spawning.
The stage of maturity of razorback sucker fry at hatching will greatly
influence their ability to survive in a pond spawning operation. When hatched,
the larvae are very helpless and it takes almost twice as to to advance to
the swim-up stages as for development o£ the embryo and hatching. The larvae
are incapable of an swimming action thus are unable to move from any ad-
< - ____-=
verse environment. When hatching,the fry will settle in the rocks and invar-
iably come to rest on a silt substrait. The probability for suffocation from
silt would be extremely high.
Close observations throughout the last 45 days gave no indications of
fry in the two spawning ponds. On four occasions a fry. seine was utilized
to seine two areas in-each of the ponds. There were no fry captured. The
author concludes that the silt problem was the limiting factor for reproduc-
tion.
The stocking program that has been proposed for this species will nec-
essitate spawning and rearing large numbers of fry. Observations of fry
and spawning in ponds give strong indications that this method will never
provide enough reproduction to fulfill the proposed stocking program unless
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