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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in late spring or early summer as streamflow decreases and water
temperature increases.
A total of 24 razorback suckers were collected in Echo Park
during a 3-week period in April and May 1975. The collections were
made with electrofishing gear and trammel nets. Since more effort
was expended at this time than during other collection periods,
relative abundance is not reflected in the total catch size. Razor-
back suckers composed 4.3% of the trammel net catch between April 29
and May 20, which is only slightly greater than their occurrence in
the 1974 and 1975 fall collections (Table 2). However, during the
spring months, 14 additional razorback suckers (making a total of 24)
were collected with electrofishing gear from spawning bars in the
lower Yampa River (see the section on reproduction). Electrofishing
gear was used most extensively during the spring of 1975, so that
direct comparison of relative abundance cannot be made with other
collections.
Flannelmouth suckers composed most of the catch from nets and
electrofishing, occurring approximately seven times more frequently
than razorback suckers in the trammel net collections and five times
more often when captured by electrofishing. Bluehead suckers and
roundtail chubs were also commonly collected at Echo Park.
Native fish comprised a smaller proportion of the total population
in the gravel pit at the Walter Walker Wildlife Area than at any
other site in the study area (Table 4). Razorback suckers totaled
0.8 to 4.2% of the catch in the wildlife area (Table 5), which was
roughly equivalent to the spring and fall collections in Echo Park.
An important distinction is that they were present in this water