7771

• UCREFRP Catalog Number: 7771
• Author: Muth, R. T. and D. E. Snyder.
• Title: Diets of Young Colorado Squawfish and Other Small Fish in Backwaters of the Green River, Colorado and Utah.
• USFW Year: 1994.
• USFW - Doc Type: \
• Copyright Material: NO

Table 1.-Diets by total-length intervals (mm) of nine fishes collected during summer and fall 1987 from backwaters in
two reaches of the Green River below its confluence with the Yampa River, Colorado and Utah. The diet measure is mean
percentage contributed by each food category to the total volume of food in each digestive tract (mean of volume percentages).
Fl anne lmouth Green
Red shiner Sand 5111 ner Fathead minnow Co 1 orado squawfi 511 Speck 1 ed dace Bluehead sucker sucker Channel catfish sunfish
Food category 11-20 21-30 31-40 >40 21-30 31-40 >40 11-20 21-30 31-40 >40 <11 11-20 21-30 31-40 >40 21-30 31-40 21-30 31-40 >40 31-40 >40 21-30 31-40 >40 21-30 >40
Upper Reach'
Insects
Un; dentifi ab 1 e parts 11 25 37 22 10 34
Semi -aquatic or terrestrial 12 <1 2
Aquatic Coleoptera 10
Corixidae <1 10 13
Trichoptera larvae 12
Ephemeroptera nymphs
Chironomidae adults 10
Anisoptera nymphs
Oiptera immatures 30 27 29 13 25 19 13 70 72 52 54 31 2B 22 70 66
Zoopl anKton
Cladocera and Copepoda <1 <1 26 16 <1 13
Rotifera <1 <1 <1 <1 16 <1
Ostracoda 14
Gammari dae <1
Hydracarina <1
Invertebrate eggs <1 <1 <1 <1
Nematoda <1 <1 10
Fish 25 29
Pl ant seeds <1 <1 <1 <1 <1
Algae 2 2 2 11 11 10 <1
Organic-inorganic debriS 35 32 22 26 50 60 64 87 93 90 31 10 13 10 10 B2 B8 90 64 51 14
Number of fi sh 45 140 63 17 40 19 108 75 26 40 305 46 12 11 18 14 19
Mean % fullness of
digestive tracts 52 64 44 38 Bl 77 73 83 B4 75 40 59 61 50 57 73 8B 7B Bl 77 63 7B 71

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