7125 ‎(2)‎

• UCREFRP Catalog Number: 7125
• Author: McAda, C. W.
• Title: Aspects of the Life History of Three Catostomids Native to the Upper Colorado River Basin.
• USFW Year: 1977.
• USFW - Doc Type: Utah State University,
• Copyright Material: YES

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Table 7. Average total lengths by age and sex for razorback suckers
from the Colorado, Yampa and Green Rivers, 1974-75. Data
under each heading includes, in order: mean, range, sample
size and standard d eviation for samples of four fish or more.
Age group Colorado River Yampa & Green Rivers
Female Male Female Male
IV 485 499
1 1
V 571 522 510 483
538-595 498-561 472-531 442-514
6 3 4 8
21.57 26.02 23.81
VI 561 510 508 489
499-609 479-541 461-539 468-515
17 5 5 8
30.71 22.06 33.26 14.43
VII 583 515
551-618
8 1
20.07
IX
592
1
in such close proximity to one another that recognition of individual
annuli becomes difficult [Tesch, 1971]. It is also possible that
the fish do not lay down an annulus every year. For these reasons,
there may be errors-in the assignment of ages to razorback suckers
in this study. Nevertheless, these assessments of age are the only
data available to provide an estimate of the growth of razorback
suckers in the upper Colorado River basin.
There was no definite distinction in sizes at different ages, but
this is common with large, mature fish. Differences in total lengths