7166

• UCREFRP Catalog Number: 7166
• Author: Miller, W. H., et al.
• Title: Yampa River Fishes Study
• USFW Year: 1982.
• USFW - Doc Type: Final Report.
• Copyright Material: NO

Yampa and Little Snake rivers
Speckled dace occurred in all strata and was the most abundant
native species collected except in Stratum 1, where roundtail chub was
more abundant and in Stratum 5, where flannelmouth sucker was more
abundant (Table 6). Flannelmouth and bluehead suckers were common in
all strata and usually comprised 10 - 30% collectively of total catch.
Numbers of these two species were approximately equal in Strata 1, 2, 3,
and 8, but the flannelmouth was more abundant in Strata 4 through 7, and
in the Little Snake. Roundtail chub was present in all strata but was
most common in Strata 1 and 2 in Yampa Canyon. Plains killifish and
Rocky Mountain whitefish were only collected above RM 59.0 (km 95.4) on
the Yampa, except for one whitefish captured in Stratum 4 at RM 54 (km
' 86.4). Mottled sculpin was found in low numbers in all Yampa strata
except 5. The species was not collected in the Little Snake River.
The endangered Colorado squawfish was not collected in Stratum 3,
but occurred in all other strata in the Yampa River. Humpback chub was
exceedingly rare; only 4 individuals were captured, two in Stratum 1,
one in Stratum 2, and one in Stratum 3. Neither of these two endangered
species were collected in the Little Snake River. Razorback sucker was
not found in the Yampa or Little Snake rivers during standardized sampling,
but 4 adult razorback in spawning condition were collected in the lower
Yampa River, RM 0.3 (km 0.5), in May, 1981, during special radio tracking
collecting. Gila spp. young-of-the-year and juveniles were collected in
all strata and were considered to be Gila robusta (roundtail chub) since
only 4 humpback chub adults were found in the study.
Exotic species comprised 15 of the 24 species found in the Yampa
and Little Snake rivers. Red shiner and redside shiner were the most
abundant of the exotic species but redside shiner was generally rare in
collections in Strata I ,and 2. Red shiner was approximately twice as
numerous as redside shiner in lower Yampa Canyon (Stratum 1) but redside
shiner became relatively more abundant in upstream strata. No red
shiners were collected above Stratum 6. Fathead minnow was found in
restricted habitats in all strata except 5, usually comprising less than
8% of the total catch. Carp was also present in all strata but repre-
sented less than 3% of the catch. Catch per effort of juvenile and
adult channel catfish for trammel nets and electrofishing, was usually
higher than for other species except bluehead and flannelmouth suckers;
however, catch per effort of young channel catfish was very low. Several
exotic species were collected only incidentally in isolated collections.
These included black bullhead, smallmouth bass, northern pike, and green
sunfish.
The largest number of species collected during standardized sampl-
ing (17) was found in Strata 6 and 7 and the smallest number (11) occur-
red in the Little Snake River. All strata except Cross Mountain Canyon
(Stratum 5) and the Little Snake River contained at least 6 of the 7
native species collected. The relatively small number of species (n=11)
found in Cross Mountain Canyon was probably due to low habitat diversity
and harsh conditions. This is reflected in the lack of backwaters and
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