7643

• UCREFRP Catalog Number: 7643
• Author: Minckley, W. L.
• Title: Trophic Interrelations Among Introduced Fishes in the Lower Colorado River, Southwestern United States
• USFW Year: 1982
• USFW - Doc Type: California Fish and Game
• Copyright Material: YES

~~' / i ,/u~ A Ii Il f .• .
TABLE 1. Summary of Frequency of Occurrence of Various Food Items in Stomachs of Fishes from the Lower Colo-ado River, 1974-76, as Percentages
of All Stomachs Examined for Each Species.
N
a,
N M
` ~,
~

~\
C ~

3`3~~

Q M

v t

C

7 h

~
.~
y
C
C

j N

C t
l~
O~ ~
~O
~ H

~

~~
.,,~
C
V

ro 4
`° ` ` Z
4 ~ O
.` ro
..c .Q
~ a ',
~ .a, ,,, H
` ~ ~
~ ,~ ~
v ro
~ .V
~ ~
w k
~°, .
O ~
O ~ ~
Q
op ~ N
J 4 ~ ~ , ~.
O -. O y . ` . N v: F
0
O ~ ro
O ::
~
S q O ro `b ~
a ~
~ ` ~
~~ ~ `~
~ a1 ~
~ ~ R ~ 1
C
` `
~ O
~~ 'b
~ z ~ ~ ~ ~ ~ a
Items in stomachs >
r
Numher of stomachs.... 38 49 135 79 i37 16 23 42 52 27 189 16 51 47 34 29 100 ri5 21 C

Tota engths, limits in x
z
miNimetres .............. 152- 37- 175- 33- 236- 93- 178- 21- 27- 118- 99- 82- 75- 78- 85- 173- 54(1- 95- 381-
440 193 864 56 737 325 813 37 64 432 560 155 205 213 305 327 893 289 495 '_~
Percentage empty.......... 18.4 0.0 7.8 11.4 16.1 12.5 39.1 Z.4 0.0 29.6 11,6 31.3 31.6 0.0 5.9 0.0 45.0 0.0 0.0 "'
2
Inorganic Materia/s ~
Sand, gravel, efc....... - 81.8 .10.4 3.8 - - - Z4 194 - 37 115 1.0 21 8.8 - - 100 951 z
Vegetative Materials
Detritus ...................... - 98.0 411 61.0 119 11.5 - - 1000 - - - -. - - - - 53.1 1000
Macrophytes .............. 16 - 1.5 - 40.9 18.8 - - - - - - - - - 4/.4 - 44.6 48
8enth(c and epiphytic ~"
algae ........................ 42.1 16.3 3.7 1.5 B.0 - - 54.8 817 - - - - - 59 - - 1?7 14.3
Fhytoplankton............ - Ib.3 33.3 - 0.7 - - - - - - - - - - - - - 143
Anima/ Malena/s
Crustacea ................... J4.3 124 74 16.6 ZQB 56.3 16.! - - 296 753 - 78 b3.8 - 103 70 - -
Copepoda .............. 29.0 20.4 0.7 21.5 - - - - - - 10.6 - 7.8 51.1 - 6.9 - - -
Cladocera .............. 5.3 4.1 3.0 11.4 - - - - - - 4.8 - - 19.1 - 3.4 - - -
Ostracoda .............. - - 0.7 - - - - - - - 1.6 - 2.0 - - 3.4 - - -
Decapoda
Astacidae............ 5.3 - 3.7 - 21.2 56.3 26.1 - - 29.6 3.7 12.5 3.9 - - 6.9 7.0 - -
Paleomoneidae .. - - - - 3.7 - - - - - 8.5 6.2 7.8 - - 41.4 - - -

Benthic Insects.......... 16..3 1b.5 33J 24.1 51 37.5 8.7 b,.y - 29.6 9.0 43.8 35.3 46.B 88
Ephemeroptera ...... - - 1.5 3.8 - - - - - 29.6 - - - - -
Odonata _ _
ZYRoptera .._ ..... - - - - - - -- - :.1 71,2 9.8
. t -r~PlerL -.. ,
,.r ,. ,
- - 16.9 4.8
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