Dodgeville chronicle. [volume] (Dodgeville, Wis.) 1862-current, 1875-09-24
Fish Culture.

ne results SO Tar atJalneQ IN this cOun-
try in the artificial culture of fish are emil
nently satisfactory, and the efforts made
by the various fisheries commissions to in
crease the supply of food for the people
are worthy of all commentator. Natural
ly, there exists a lively public curiosity to
know the processes of fsh-cu]ture and in
formation with regard to its history, its
principles and its methods is heartily
welcomed. In response to this general
| demand, Mr.. Robert B. Roosevelt, Fish
Commissioner of the State of New York,
has given a public lecture on pisciculture,
in which he very fully considers the sub.
| ject in all its aspects. The lecture is very
long and we must be content with indicat-
ing only few of its points. There are,
he said, two divisions of fish in our coun-
| try which are subjects of fish-culture
namely the Salmonidn, or salmon-tribe,
and the Alosidoe, or shad-tribe. Under
the former head are included the salmon,
| the trout, the salmon-trOut Tor lake trout),
the white-fish and the California salmon.
| The Aloside are represented in piscIcult-
ure only by the shad, as yet.
The first point in fish-culture is to OBJ.
tain the spawning fish in proper condition.
In the Salmonide, the eggs, when in a
perfectly ripe condition, lie free in the
abdomen and may be extruded by gentle
pressure. They are caught as they fall in
basin and are vitalized by coming in
contact with the milt from the males.
Formerly, the practice obtained of having
this basin full of water, it being supposed
that this arran cement more nearly repro
duced the natural conditions; but subse-
quent discoveries led to change of this
method. The eggs are fertiliZed by the
spermatozoa of the milt entering through
the micropyle and taking up board and
lodging within. 1t was ascertained, how
ever, in practice, that these spermatozoa
are not fond of water, and although very
active when first emitted, soon drowned.
They retain their vitality much longer
when dropped among the eggs in a COM
paratively dry state, and this is the method
universally pursued at present.
AS soon as the operation is completed the
eggs are placed in Matching -troughs.
These are made of various materials, but
are simply long, narrow boxes, say twelve
feet long by eighteen inches wide, and
subdivided into apartments to keep the
eggs from crowding on one another Cold
spring water, which has been carefully
filtered by passing through several flannel
screens, comes in at the head of these
troughs, passes over the eggs in one COM
partment after another and escapes at the
lower end. By this means the greatest
dangers to the life of the embryo are avoid
ed. Sediment and conferve cannot pass
the screens, insects are kept out altogether,
and ducks and cells are disappointed of
their prey. The eggs require about two
months to hatch, with the water at the
temperature of forty-five degrees. They
demand constant care and attention, for if
one egg dies or becomes diseased it con-
teammates its neighbors. The advance
of the process is, however, soon visible in
the egg, either to the human eye or under
the microscope. AT last the pisciculturist
will have evidence of his labors being
successful. Some morning on going to his
troughs he will notice broken egg-shells in
the water, and on closer inspection will
observe wiggling nondescripts on the bot
tom, neither like fish nor eggs, but COM
pounded of both. When they once begin
to appear they come in thousands, in mill
ions, in myriads. The young need more
water at this time, but require less care
yet still they must be watched. The
young fish may soon be turned loose into
the stream.
If he is a salmon after few months
preparation to strengthen his sinews and
test his power he goes down to the sea,
there to dwell, and feed and grow, gaining
wonderfully in size, drawing his susten-
ance from the exhaustless storehouse of
the world, and coming back to man in a
few months a magnificent embodiment of
strength and beauty, bringing to the lord
of the universe five or ten pounds of as
delicious food as ever delighted gour-
mand's palate, or satisfied hungry mans
stomach. If he is only a trout, younger
brother of the glorious family of Sal
monide, he will Turk about the bottom of
some pond, or Craze the pebbly mountain
brook, and struggle up to a halfpound or
more before twelve months shall have
rolled over his head.--Popular Science
Monthly.