7214

• UCREFRP Catalog Number: 7214
• Author: McAda, C. W. and R. S. Wydoski
• Title: Growth and Reproduction of the Flannelmouth Sucker,
• USFW Year: 1985
• Copyright Material: YES

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GREAT BASIN NATURALIST Vol. 45, No. 2
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ANNULUS
Fig. 2. Mean total length and growth increments at annulus formation for male and female flannelmouth suckers
from the Gunnison, Colorado, Green, and Yampa rivers, 1975-1976. Numbers indicate sample size. Bars indicate one
standard deviation.
The diameters of preserved, mature ova
ranged from 1.99 to 3.15 mm (mean=2.39
mm; n=49). The relationship between ova
diameter and fish length was not significant
(P>0.05).
Fish from the Yampa and Green rivers pro-
duced significantly fewer mature ova than
did fish from the Gunnison or Colorado rivers
(P<0.001: Table 1). Flannelmouth suckers
from the Gunnison River also produced sig-
nificantly fewer ova than did those from the
Colorado River. Based upon the regression
equations, a fish 450 mm long from the Yam-
pa River produced about 9,800 ova, whereas
fish of this length from the Gunnison and
Colorado rivers produced about 12,700 and
15,900 ova, respectively.
Ripe male flannelmouth suckers were col-
lected from both study areas when sampling
began in early April and on through June.

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