84 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
spieuous, especially when t hey collect in bunches. One such bunch in Olema Creek, 
in which there were four or live thousand, could be plainly seen from a point 50 yards 
distant. In such instances they are very much exposed to the ravages of ducks 
and geese — both tame and wild — herons, cranes, and other wading birds, and even 
of hogs, to say nothing of the fish in the stream. Alevins are very tempting mor- 
sels, and there is scarcely an animal that will not eat them when given a chance. 
However, most of the alevins can get into crevices between and under the pebbles 
and bowlders, where they are much safer from the attacks of the fish that may be 
in the stream than they would be if they were in the pools or quiet places. 
Observations were also made on planting alevins in Sullaway Creek near Sisson. 
This is a very favorable stream in which to release young salmon, so far as preda- 
ceous fishes are concerned. The only fishes of the stream are rainbow trout, scul- 
pins, and quinnat salmon parrs remaining from the season before. The plants were 
made on the riffles, but as these were all rather short, many of the alevins drifted 
into the pools. They were liberated in the morning, and in the afternoon the pools 
were seined with a small-meshed net. The fish caught were examined to find to 
what extent they had eaten the alevins. The result is shown by the following table, 
which giv.es the length of each fish examined and the contents of its stomach: 
Species ex- 
amined. 
Size, in 
inches. 
Number 
alevins 
eaten. 
Other material in 
stomach. 
Species ex- 
amined. 
Size, in 
inches. 
Number 
alevins 
eaten. 
Other material in 
stomach. 
Trout 
6 
17 
1 small pebble. 
Sculpins 
3.5 
3 
5.5 
9 
6 insect larvae. 
3. 5 
4 
5 
7 
1 caddis larva. 
3.3 
2 
4.5 
6 
3.3 
2 
3 insect larvae. > 
2.5 
0 
Insect larvae. 
3.3 
3 
2.5 
0 
Do. 
3 
2 
Salmon parrs. 
3.8 
1 
3 
2 
1 insect larva. 
3.5 
1 
2.8 
2 
3.5 
1 
2.8 
2 
3.5 
2 
2.8 
2 
3.5 
2 
2.7 
1 
3.5 
2 
2.4 
0 
3.5 
2 
1 insect larva; 1 
2.4 
1 
water bug. 
2.4 
1 
3.4 
1 
2 
0 
3.4 
1 
2 
0 
3.4 
2 
Species and size 
3 
i 
2 winged insects. 
unknown 
3 
In the case of the largest trout, 6 inches long, 7 of the 17 alevins were in its throat 
and mouth. It had evidently gorged itself to the limit. 
In all cases where salmon parrs had eaten two alevins, the tail of the second 
remained sticking out of the mouth, their stomachs being large enough to accommo- 
date only one. The sculpins also had gorged themselves in the same manner. All 
of the fish caught were examined and only three had not eaten alevins, being too 
small. Three alevins had been disgorged by some of the fish. Evidently alevins 
are a favorite food for trout, sculpins, and salmon parrs; and when they remain 
exposed to such enemies from 2 to 1 weeks, it is a wonder that any escape. 
Alevins planted in the Marin County streams in 1898 met even a worse fate. Here 
the trout are more numerous and larger. The sculpins are also larger and more 
abundant. There were no salmon parrs to feed on alevins, but there were myriads of 
sticklebacks, which, though unable to swallow an alevin, killed many by nibbling at 
the yolk. The only other fish in these streams was the roach ( Kutilus symmetricus), 
which as far as could be learned did not feed on the alevins. Four is a moderate 
