The sun. [volume] (New York [N.Y.]) 1833-1916, 1905-03-19
1000 NEW LITTLE FISHES
That Number Added, Within six Hours, to
the Population of the Aquarium.

That Number Added, Within six Hours, to
the Population of the Aquarium.
The fish population Of the Aquarium
was on Wednesday last increased in the
course OF six hours by about 1900, includ-
ing 1900 tiny whitefsh and 5000 little lake
trout, which emerged on that cay and
within that short period from as many eggs
which had been in process of incubation
in the hatchery. The reason for the final
Matching out Of all these eggs practically
all at once was very simple.
The natural period Of incubation of the
eggs Of fishes Of various species varios
greatly, and the incubatinR period of the
eggs Of apy particular species varies accord
ing to the temperature Of the water in whic1
they are placed. Any raising of the tenn
perature above that to which the eggs
would have been subjected in nature so-
CELEBRATES the Matching.
whitefsh eggs, for example, commonly
hatch out in from 100 to l25 days, according
to the temperature OF the water With
Croton water Of the uniformly cold tempera-
ture at which it has been running this spring
it had been expected that the whiteish eggs
in the Az uarium would run their full period,
to hatch out about ten days hence.
bul on wednesday ldHN lho aquarium y
fresh water supply main was temporarily
cut OF outside the building TO make repairs,
and. with this cutting of Of the constant
inflow Of cold water, the water in the Aquar-
ium tan ks began TO rise in temperature.
In the shallow troughs and the small jars
Of the hatchery it rose twelve degrees before
the continued flow Of cold water was
restored
Promptly with the rise in the temperature
Of the water the egg OF the Whitefsh and
lake trout in the hatchery, already well
advanced, began to hatch out. A few
scattering little whitsfsh had appeared
In the course OF the previous week, but
now they began to come out in numbers,
Whitehsh eggs are not Matched in troughs,
but in Matching jars. Through one pipe,
entering at the top OF Matching jar, runs
q constant stream OF water, which keeps
the eggs in gentle motion and aeTated.
Another pipe running out OF the top Of
the jar serves as a siphon to tao away
the overflow water, and through this pipe
also are carried of the Matched out fishes
to a tank adjoining
The fish eggs tend toward the bottom
OF the jar the Matched out little fishes risA
TO the top, 20 be caught by the outflow and
carried over through the siphOn tube TO
the larger tank waiting to receive them.
In this jar Of whitefish eggs az the Aquar-
ium when the temperature began 70 rise
their eggs at the bottom ia droyes, and
TO rise and wriggle and swim 20 tho upper
water in the jar, there 10 be caught in the
siphon current and carried up and over
and then down into the waters OF the tgnk,
and thus 0 900 Of them came out Of their
eggs and went over as little fishes within
| the space OF six hours, 500 little fishes an
| hour, an average Of twenty-five a minute.
There are still a few slower whtefSh
| eggs remaining to be Matched in tho jar,
| but the bulk OF those that were there were
Matched out In those six hours, a. wcra
within the same period about 500 young
| lake trout, from eggs in troughs, which,
with a continued flow Of cold water, would
| have required about two weeks more for
| Matching.
The new little whitehsh, in their glass
sided tank, can be very plainly seen. They
are necessarily in motion, bu', "a Is true
Of the young Of many SPECIES Of fishes,
! they incline TO mass together, 20 that they
| look In the water as a swarm Of little flies
| might look in the air. Il II this keeping
| together OF the little fishes IN nature that
costs innumerable millions 81 young fish
| lives. big fish in search Of food swim
| ming through such a swarm Of little fishes
| in their native water would suck in tho4-
sands Of them at a gulD