NATURAL HISTORY OF THE QUINN AT SALMON. 
83 
tne ocean makes it <juite certain that the time is determined by other influences than 
the season. If so, it is doubtful whether those planted in Paper-mill Creek would 
have any advantage over those planted in the Sacramento River. 
Planting alevins . — Alevins on being liberated in swift water swim frantically 
anti scatter in all directions as they are swept downsteam. Most of them seek the 
bottom and crowd into crevices between the pebbles or get into quiet places under 
or behind large bowlders. Others find their way into still water along the edge of 
the stream, where they remain exposed to view. In moderately swift water some 
find a lodging-place on the bottom or near the shore before they have been carried 
a hundred feet downstream, and it has to be very swift water that will carry them 
a hundred yards. For several hours after being planted in swift water many of 
them keep moving about. Often the place where they first lodge is too much 
exposed to the current, and they are repeatedly swept downstream, lodging here and 
there for a few moments, until they finally reach a quiet place where they can stay. 
After a few hours this moving about ceases and they remain quiet, retaining 
their places for at least several days. In one instance 60,000 alevins were liberated 
on a very swift riffle in Sacramento River 200 yards above a quiet pool. The riffle 
was shallow, at no place over a foot deep, but so swift as to make it almost impos- 
sible for a person to stand. The alevins all found shelter before they were carried 
a third of the distance to the pool. On visiting (lie riffle a day later none could be 
found much over a hundred yards below the place of planting and none was found 
in the pool below, which was seined thoroughly. All had found sheltered places 
and had ceased to move down with the current. When alevins are planted only a 
few yards above a pool, even in moderately quiet water, large numbers will drift 
into it, where they remain if they are not eaten by trout or other fishes. 
When alevins are liberated in a pool or pond they at first scatter out near the 
surface, but soon settle to the bottom, where they keep up a constant wriggling of 
the tail and pectoral fins. Within a day or so they collect in bunches, appearing 
as brilliant salmon-colored blotches over the bottom of the pond. The constant 
motion of the individuals stirs up the silt until it is washed away from them and 
each bunch rests on the solid bottom. Alevins in a hatchery, by this constant 
motion, keep the hatching-trough free from sediment. 
During a freshet at the California State hatchery at Eel River a thick sediment 
of sand was washed into the hatching-troughs and came so fast that the alevins, 
just hatched, were unable to keep it from settling. It covered the bottom of (lie 
troughs to a depth of 2 inches, becoming hard and compact. The alevins, instead 
of being covered, were found above the cement-like deposit, and none of them had 
been lost. This interesting incident demonstrates their ability to keep from being 
covered by sediment during a freshet, whether they be in pools, ponds, or troughs. 
Alevins in the pond at the Bear Valley hatchery began swimming about in 
schools before the yolk-sac was entirely absorbed. The presence of predaceous 
fishes might have caused them to do otherwise. 
Enemies . — When alevins are planted on riffles they are inclined to congregate 
in eddies and sheltered places behind bowlders. In these places several thousand 
of them may be found huddled together in a bunch plainly exposed to view. They 
are not very shy at this age a-nd do not appear to try so much to get out of sight as 
to get out of swift water. The brilliant salmon color of the yolk makes them very con- 
