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FOREST AND STREAM. 
[April 24, 1909. 
Water Supply for Trout Hatcheries. 
Editor Forest and Stream: 
“Water is the beginning of all things,” said 
a Greek philosopher. Success in artificial trout 
culture depends mainly on the knowledge of 
the water and the method of handling it prop¬ 
erly to hatch impregnated eggs successfully, as 
well as to rear adult trout. The first condition 
is that the water must be pure and rich in 
oxygen, in order to give the young fry the 
necessary supply. The water must run in the 
open air so as to carry off the carbonic acid 
exhaled by the fish. 
Some trout culturists take the water directly 
from a spring, others from a running stream 
or river. I wish to explain herein, as far as 
I am able, the relative advantages of the above 
mentioned methods. The closer to the spring 
the water is taken the poorer it is in oxygen. 
advisable to clean the pipes after the middle 
of October. As soon as the young fry begin 
to take food, the water flowing through the 
supply pipe will carry along with it great quan¬ 
tities of suitable food and help to feed the fry. 
Of course all water filters must be discontinued 
when the young fry start to feed. 
I would also recommend that any pipes carry¬ 
ing water to a hatchery should have two or 
three good sized tanks along their course in 
which the current of water may deposit sedi¬ 
ment. Tanks from six to eight feet long, three 
feet wide and two feet deep will answer the 
purpose. It is recommended to conduct water 
to a hatchery by means of pipes or troughs 
where the land has not much fall, but when 
the surface is sloping, artificial races or rivulets 
are preferable. The best mode of constructing 
such races is in a winding direction, with gravel¬ 
ly bed, and furnishing here and there small 
vigorous and of remarkable vitality. 
In water of a higher temperature than 55 de¬ 
grees the development of the embryo is very 
rapid and the fish which result, though appar¬ 
ently sound, will never reach a normal condi¬ 
tion and generally remain weaklings or die 
shortly after liberation. For this reason it is 
not advisable to hatch trout eggs near a spring 
where the temperature of the water is over 54 
degrees. The further the water runs through 
the open air in winter the better for success¬ 
fully hatching trout eggs, because the cold air 
lowers the water temperature considerably and 
the process of hatching is retarted. 
In conclusion, to hatch trout eggs successfully, 
cold and well aerated water is necessary. Spring 
water supplies the necessary conditions as far 
as purity is concerned, but this is unimportant 
in comparison with properly oxygenated water 
because impure water taken from creeks or 
TROUT HATCHERY PONDS. 
Part of the private ponds of “Ransacker,” in the Shasta Mountains in California. 
This is easily understood because the water has 
had no chance to come in contact with the air. 
This being the case it is necessary to carry 
spring water some distance through the open 
air in order that it may become aerated. If 
the water can be conveyed only 100 yards to 
150 yards through the air through a pipe or 
a rivulet it will become charged with sufficient 
oxygen and will convey the elements necessary 
for the proper development of the eggs. 
If the water is led through an open trough 
into the hatchery the trough should be built so 
that the water will fall over a number of little 
cataracts. If these are only two inches high 
and three or four yards apart they will answer 
the purpose. The trough should have an in¬ 
cline of from one to two inches in every four 
or five yards. The greater the distance the 
water runs through the troughs or rivulets be¬ 
fore it reaches the hatchery, the more oxygen 
will it contain. The pipe or trough should be 
supplied with several small openings along one 
side in order that it may be cleaned out when 
necessary. To clean the pipes a board partition 
is placed below the opening, and on opening the 
sluice the pipe can then be closed easily as far 
as the partition. 
The moss which grows in such pipes or 
troughs is one of the best water plants for the 
reproduction of plankton and Crustacea, for in 
this the Crustacea deposit their eggs. But it is 
basins in which the water may deposit sedi¬ 
ment. Basins similar in size to the tanks above 
described in connection with the water pipes 
will be amply large. They should have an out¬ 
let at the bottom so that they may be cleaned 
when necessary. Through the above described 
races the water will reach the hatchery in per¬ 
fect condition. In running over a gravelly bed 
it will lose the sulphurous gases which are so 
frequently present in spring water and which 
would destroy the impregnated eggs. 
By conveying the water through long troughs 
or rivulets (races) to the hatchery, its tempera¬ 
ture will be lowered in winter from 10 to 15 
degrees Fahrenheit or more, which will greatly 
help the development of the eggs. 
The temperature best adapted to brook trout 
and rainbow trout ranges from 40 to 55 degrees 
Fahrenheit. It might be 35 degrees Fahrenheit 
without injuring impregnated eggs in any way, 
but should not be higher in temperature than 
60 degrees. Rainbow trout eggs have been 
hatched in water of 65 degrees, but the fish 
which are liberated generally die or they are 
not vigorous. Further, many eggs burst dur¬ 
ing incubation because development of the em¬ 
bryo is too rapid in a high temperature of water. 
Impregnated trout eggs may remain in troughs 
two or three weeks in water at a temperature 
of 33 to 35 degrees Fahrenheit without any in¬ 
jury; on the contrary the fish which hatch are 
rivers can be readily purified by settling basins 
and filters. Where one is compelled to build 
a hatchery near a spring the water may be 
aerated artificially. August Lauth. 
Trout Flesh Color Variations. 
U. S. Bureau of Fisheries, Spearfish, S. D., 
April 16 .—Editor Forest and Stream: Edward 
B. Rice, in his article on “Rainbows- that ‘Hop,’ ” 
in your issue of March 27, stated that they 
were all white fleshed. Perhaps some of your 
readers will be able to tell me— 
(1) Whether white flesh is more common 
among rainbows than brook trout? I have an 
idea that salmon colored flesh is characteristic 
of the fontinalis. Is this a mistake? 
(2) Is it uncommon to find a stream or lake 
with white fleshed brook trout containing other 
species of trout with pink meat? 
(3) As a rule are there any indications of 
overstocking where many white meated fish are 
found ? 
(4) Have any observations been made re¬ 
garding the proportions of these white fleshed 
trout to determine how they compare when at 
their prime with pink fleshed fish of the same 
species of standard proportions in other streams? 
Any observations about localities in rivers 
where flesh color varies from that found on 
the rest of the river will be of interest. 
George P. Bosanquet. 
