The sun., 1897-05-09
CARE OF CAPTIVE FISHES,
THINGS ESSENTIAL TO THEIR VEL.
FARE IN 1OCIRIUMS.


In which They Are kcpt-For All. Fm,rn.
tion nnd Aerntiont for Some. Refrigeration
ns We'll, TOR Others. Heating.
The proper care OF fishes in aquarums in.
wolves very much more than merely placing
thom in tanks and feeding them. The water in
the tanks is filtered and aeratcd II may need also
TO bo refrigerated or heated. Filtration may
conduco 10 the welfare OF the fishes; II is essen.
tial to their most advantageous exhibition
Acration Is essential 10 tho existence of all
fishes; refrigeration or heating may be essential
to the existence of some.
There are various methods OF fltering and
various coagulants are used, alum, however,
most generally. Particles, as for example, OF
fine silt that separately might pass through tho
filter. being finer than tho llltcrlng medium,
which is charcoal or sand and gravel, are by
the use OF coaguant, assembled into larger
masses. These aggregated masses are still cx
tromcly minute. but they are sufficiently large
to bo caught in the filter
At tho New York Aquarium pressure filters
arc used for fresh water and the coagulan, is
alum. Fitering may free water from impurities
that would be injurious TO fish, but its chief
purpose is to clarity 1t so that tho water itself
may be clear and slightly, and so that the fish
can be better seen In it, and IL water we're used
unflltered sediment In larger quantities would
settle upon the glass or upon the bottom Of Tho
tank and the tank would then require more
frequent cleaning, necessitating perhaps 'hs
temporary removal OF the fishes, and tho han.
ding or other disturbance of them, all apt to b,
more or less injurious.
is not srticiaiiy filtered, as is commonly DONE
and as was originally done here. The building in
which the AQUARIUM , Is located sta stands upon,made
d we'll wa was sunk sunk, from Witch is obtsinsd s%pps
OF salt water ample for the wants OF the Aqua
rum. The water is pumped directly into tho
main supply tanks clearer than IL Il had been
through what is in effect great natural hitter.
The tide in tho we'll rises some hours later than
stands: in temperature the water from the well
is about five degrees warmer In winter and tivo
degrees cooler in sumner me TN than ,h IN the BAY m
all living water contains more or less air. il tho
water becomes stagnant and dead the fishes in it
time taking in water under tho gill covers pass.
ing 1t over the eills and out through the mouth.
OF out under the gill covers The gils are In effect
the fishes lungs. In the gills there are many
them. from the water constantly passing over
the gills air is absorbed into the fishs blood for
In nature the fish is in a comparatively large
body Of water; IL the fish is In motion It Is in
water that is constantly new to Il; II II should
remain stationary new water would be brought
in small streams good sized or large fishes find
being aerated BY taking air into its water as il
tumbles over rocks From water of the limited
bulk of that in Aquarium tanks. unless means
were taken to keep it constantly renewed. the
fish would soon exhaust the oxygen. that part OF
Some aquarium tanks are made seif.sustainins Ming
by the INTRODUCTION of Just the right amount OF
% al and dbtR tho sess stS
sweet by the inflow Of new water. the surplus
running off by an overflow pipe. The new water
is constantly bringing new stores of air to he
diffnsed through the body of water in the tank.
All great aquariums have one practice In COM
water is let fall through the air for a distance
OF few feet II gathers air in this fall; and the
ton Of its SIS Surface caused by the falling Wafer
The air thus taken IN goes into the circulation.
sary io cut out f saoR or
of tanks. air would hav" to be supplied in some
other manner. There , are many , ways ways in which
rum tanks.
a common way is by the very simple method
per and pouring it back through the air. Air 10
something's pumped into tank with an ordinary
however. COMES oH' to the e. surface again in bSbbes
Large aquariums are fitted with a permanent
are numerous Ways in which this is accom-.
plished. By the method adopted at the Aquarium
rate outlet for each tank. To, each outlet is at
rubber Sn Pps In %hGh n Is reed
the basswood 50 finely divided that it makes u
light cloud OF vapor In the water. The air may
be supplied to the tanks separately, TO one tank
or to any number OF tanks at once: and the pres.
sure may be regulated at each tank.
This means of air supply is sometimes used
also when tanks are i'll circulation to make up
for deficiency in natural aeration. which some
Fishes in nature seek waters of a temperature
that suits them. Fishes in salt water. hereabout
proach OF summer growing too warm for thcnr.
go further north or of shore into deeper watFr.
cod eS Moed South sSes
harder than others and stand changes OF tenn
perature better. There are some that in aqnari-
ums are sure TO die unless the temperature
Of the water s in their tanks approXim"es
or salmon, for Instance alive in w@tcr
at temperature of 75' or upward, which is
summer II such fishes are TO be kept alive in
tanks the year round the waters which they liys
eans IN Of pc IN
be set up at the New York Aquarium rcfris.
plant that i is viii keep 6i
employed will DO by the liberation OF com.
pressed air or by ammonia absorpt on which Il
The water is cooled in a tank containing
coil through which the cooling medium Is
in the usual manner to the tanks con, dining
The fish. Twelve tanks will be thus sunn!lcd AZ
will not bo permitted to run to waste, but vii!
be piped to receiving tank. from which II WI.
fhf 6e nS
arc supplied. The cooled water IS thus nsSh
over and over again. IL reaches the rcrrlNihs
tank but little higher in temperature than when
It left the cooler. II of course. constantly rising
in temperature. and in delivering il again int"
the storage tank it is run through spra{inE
nozzle for purposes of acration. there absorbing
more heat; but IL reaches the storage tank and
flows through that and through the liter and
finally reaches the cooler again still much cooler
than water drawn from the main would he, and
loss energy is therefore required to reduce II 10
the temperature desired.
Tho heating apparatus is to heat water for sag
water tanks In which tropical and Sub.troplcm
fishes are kept. These fishes. including for
example, the SNOWY fishes OF bermuda a..
Customed in nature to warm waters, cannon ..
kept alive through the winter in the wat"rm
this latitude Mt its natural Temperature: nr
the New York Aquarium compriscs hoilcr'!ik'
tank In which n coil is placed. The water rinI
from storage tank direct to the heater; nrill' l
filtration of the salt water used not being nr. -
sary for the reason that il comes from / he -h't
water well already pictured. Tho water Is llril'1
chiefly by exhaust steam. which u lAS-"u
through tho coil in the heater. II necessary IN
very cool weather live steam also can he ln','
tuCpd The anlt ia returned 10 mo