118 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Classification of the insect food of young salmon . — Tlie following is a classified 
list of the insects found in the stomachs of young salmon from the Sacramento 
River, collected during this investigation, as reported by Miss Bertha Chapman. 
It is evident that in many cases the fish confined themselves largely to food collected 
at the surface of the stream, as is the case with fish taken at Rio Yista in May, or 
those taken at Fall River Mills in August; others sought the immature forms living 
under water, as can be seen from the majority of cases in the list. But in no case 
can this distinction in feeding habits be definitely made. They seem to have fed 
indifferently on water and surface forms. These surface forms are almost invari- 
ably insects living about streams, and which might therefore easily have fallen into 
the water from overhanging plants. Much of the stomach contents had been so far 
digested that it was not possible to identify t lie insects. Other insects have been 
partially determined by single wings or particles of the body; but it seemed not so 
important to carry the classification to species as to determine the types of insects 
forming the food of young fish. The results of the study are given in the following 
table : 
Classification of insect food for young salmon. 
Place. 
Date. 
ft 
c n 
ft 
*o 
5 
ft 
a 
j Libellula. 
Ephemerida. 
Plecoptera. 
oi 
5 
-*-> 
o 
ft 
5 
$ 
d 
o 
fi 
d 
;s 
o 
O 
9* 
d 
ft 
d 
£ 
| Notonectidse. 
82 
d 
’55 
ft 
d 
O 
82 
m 
d 
d 
S 
d 
'v 
d 
'd 
<D 
ffi 
CD 
cu 
82 
d 
2 
ft 
d 
S 
-e> 
ft 
O 
ft 
o 
0> 
u 
H 
Lepidoptera. 
oj 
s 
-e» 
5 
8 
(d 
S 
82 
[d 
<D 
o 
o 
d 
ft 
ft 
<D 
s 
82 
d 
"o 
5 
Chironomidte. 
Ceratopogon. 
82 
d 
d 
9 
/ 5 
12 
do 
39 
X 
1 
t 
1 
XI 
February 
do.... 
+ 2 
3 
+ 
+29 
t 
2 
t 
1 
2 
+ 
March . 
1 
+23 
t 
1 
/I 
t 
t 
2 
do.... 
+30 
+ 
* 
Benicia (brackish ) 
do _ .. 
4 
12 
:::: 
+ 
April 
‘ do 
2 
i 
2 
p3 
+1S 
t 
- 2 
± 
.. .do 
+28 L- 
* 
/ 5 
p2 
s 
1 
1 
pi 
i 
XI 
13 
do.... 
4 
(1 
xi 
XI 
1 
3 
t 
2 
14 
do 
(1 
Xp 
+ 
tp 
1 
Red Bluff 
... do 
5 
p2 
/ 2 
do . 
2 
o 
2 
13 
12 
do 
L ' 
tp 
tl 
1 
... .do 
2 
1 
Xp 
do 
3 
+1 
... do . . . 
3 
1 
XI 
..do _ 
2 
pi 
Knights 
...do.... 
1 
do... 
5 
x 
2 
+ 
Benicia (brackish) 
Pinole (brackish ) . 
Point Richmond 
"" 
3 
3 
t 
2 
t 
+ 
...do ... 
2 
t 
9 
1 
2 
+ 6 
XI 
+ 
+ 
... 
1 
X 
X 
3 
5 
... 
+ 
+7 
Hazel Creek 
do 
+ 6 
t 
XI 
X 
2 
4 
1 
1 
1 
p2 
+z 
.. do. . 
1 
+ 
... 
3 
1 
5 
ti 
1 1 
14 
.. .do ... 
1 
1 
+ 
pi 
+ 
4 
1 
i 
1 
+ 
1 
X 
12 
5 
+ 
X 
xi 
x 
XI 
Sul la way Creek . . 
September 
do ... 
+12 
2 
2 
2 
+9 
2 
3 
xp 
pi 
i 
3 
1 
+ 
X 
do ... 
+12 
n 
i 
n 
2 
6 
1 
« 
n 
tl 
X 
x 
xl 
. .do 
5 
20 
6 
XI 
Xp 
xi 
do 
+ 
+ 
1 
2 
i 
i 
t 
t 
i 
1 
1 
2 
p2 
n 
13 
10 
2 
2 
5 
r 
. . .do 
+14 
+ 
t 
2 
x 
XI 
