7129 ‎(2)‎

• UCREFRP Catalog Number: 7129
• Author: Barham, W. T., H. J. Schoonbee and J. G. J. Visser
• Title: Use of Electronarcosis as Anesthetic in the Cichlid,
• USFW Year: 1989
• Copyright Material: YES

I ISSUE 3, 1981 FOOD OF CHANNEL CATFISH 93
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Figure 2. Mean percentage of wet weight biomass of
food items in channel catfish stomachs, by
size group, from three stations in the
Coachella Canal, California. (+ indicates
less titan 0.5%.)
Aquatic Lepidoptera larvae, Parargyractis con/usalis, were
in almost 627c of stomachs and accounted for 1.27c of total
biomass. Utilization was highest at Station A and lowest at
Station B. Frequency of occurrence was about 50% in smaller
fishes (<150 mm TL) but 80-89% among fish of >150 mm
TL. Mean individual weights (3-6 mg) were similar to S. utico.
Ephemeroptera nymphs, Baetis sp., were in about 18% of
all stomachs and had a frequency of occurrence ranging from
13% at Station A to 60% at Station B; however, mean numbers
were low (0.15-0.43 per stomach). The contribution of Baetis
sp. to total biomass was small, 10 mg overall. Utilization of
Baetis sp. was greatest by fish of 200-299 mm TL.
Nectopsyche sp., a cased leptocerid caddisfly, occurred in
more than 26% of stomachs. Although generally in small
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Figure 3. Mean percentage frequency of occurrence of
food items in channel catfish stomachs, by
size group, from 3 stations in the Coachella
Canal, California. (+ indicates less than
0.5%.)
numbers (x = 3.56), one catfish (256 mm TL) contained 167
Nectopsyche sp. individuals. Their contribution to total
biomass was small except among larger fish (> 200 mm TL) at
Station A. Mean individual weight of Nectopsyche sp.
(including case) was 6 mg.
Crayfish, Procambarus clarki, were in only a few stomachs
(35/c of total) and in small numbers (1-3 per stomach).
Utilization was greatest (up to 20%) by larger catfish, but their
contribution to total biomass was small.
Fish accounted for only 3% of the overall diet. Threadfin
shad, Dorosoma petenense, remains were found in two catfish
at Station A, one (TL = 252 mm) contained scales and bone
fragments, the other (TL = 394 mm) contained two entire