20
Aquatic
_
deep, to require two 60 W tungsten lamps burning for 8 hours or
_
’
more a day.
.
_
…
_
.
Fishes do not require absolutely fixed‘intensities: or d‘uratiohs of
light, but they do have prèferences which presumably refleCtthe
'
fact that they come from various natural environments and have
'
many
characteristics which are strongly influenced by'light.f—The
popular range of aquarium freshwater fish can be divided roughly
into those which delight in intense light and swim and feed just _,
.
,
below the surface and in the middle waters, those which inhabit the
bottom and dark corners and are suited to dim lighting,'and thoSe
which are usually nocturnal. The intensity of light definitely seems
to have an effect on the ‘happiness’ of some of the more sensitive
fishes. Some Cichlids for instance will not do at all well unless they
can hide in caves or under plant growth away from strong light. If
’
these facilities are not provided the fish may become ‘neurotic’and
illness or death may follow because they do not feed properly.
Generally the Tetras,‘ Danios and many Barbs and similar fish, parti—
_
cularly those which shoal, like or tolerate strong lighting, while
Cichlids, Catfishes and the more individual fish prefer shadyàiding
places in bright environments or dim lighting in more open
ments. It,is surprising how a change of lighting will alter the balance
.
between fishes in a community aquarium. For instance apreviously
,
"
meek, nervous specimen maybully the wholegy_,populatio,n _if the
'lightingis
While _abullÿ used‘Ïto
driven ‘uñderground’ by an
with the
type of light falling “upon it; So that
'
_,
a particular fish will only look its best in the right light.
_,COmpletely change their colours and camouflage patterns With
'
—of1ighr. ,
'
'
_
_
_
duration of illumination in artificial situations
Ï
either partially or wholly the length of
day. Within reason
influence their feedinghabits and hence their rate of
'Çertainly
ofrëgular amounts of light; coupled»
.“] '
tends to; keep
.
'
,
Îsùmmertime condition, so that»other
désirable, but itisvirtliàlly ntblwhthvlbllght
art1f1c1al Also,
receive“ the annualcychcreper10dsto
and this "may: shortenÂ-théirlife span}
canbe madeiohthis
'
_
ne feature ofdomest1chfewhrch
rev10usly ,lived in
is the sudden sw1tchmgon
î
a{' a «
_______…______:
Aquatic
_
deep, to require two 60 W tungsten lamps burning for 8 hours or
_
’
more a day.
.
_
…
_
.
Fishes do not require absolutely fixed‘intensities: or d‘uratiohs of
light, but they do have prèferences which presumably refleCtthe
'
fact that they come from various natural environments and have
'
many
characteristics which are strongly influenced by'light.f—The
popular range of aquarium freshwater fish can be divided roughly
into those which delight in intense light and swim and feed just _,
.
,
below the surface and in the middle waters, those which inhabit the
bottom and dark corners and are suited to dim lighting,'and thoSe
which are usually nocturnal. The intensity of light definitely seems
to have an effect on the ‘happiness’ of some of the more sensitive
fishes. Some Cichlids for instance will not do at all well unless they
can hide in caves or under plant growth away from strong light. If
’
these facilities are not provided the fish may become ‘neurotic’and
illness or death may follow because they do not feed properly.
Generally the Tetras,‘ Danios and many Barbs and similar fish, parti—
_
cularly those which shoal, like or tolerate strong lighting, while
Cichlids, Catfishes and the more individual fish prefer shadyàiding
places in bright environments or dim lighting in more open
ments. It,is surprising how a change of lighting will alter the balance
.
between fishes in a community aquarium. For instance apreviously
,
"
meek, nervous specimen maybully the wholegy_,populatio,n _if the
'lightingis
While _abullÿ used‘Ïto
driven ‘uñderground’ by an
with the
type of light falling “upon it; So that
'
_,
a particular fish will only look its best in the right light.
_,COmpletely change their colours and camouflage patterns With
'
—of1ighr. ,
'
'
_
_
_
duration of illumination in artificial situations
Ï
either partially or wholly the length of
day. Within reason
influence their feedinghabits and hence their rate of
'Çertainly
ofrëgular amounts of light; coupled»
.“] '
tends to; keep
.
'
,
Îsùmmertime condition, so that»other
désirable, but itisvirtliàlly ntblwhthvlbllght
art1f1c1al Also,
receive“ the annualcychcreper10dsto
and this "may: shortenÂ-théirlife span}
canbe madeiohthis
'
_
ne feature ofdomest1chfewhrch
rev10usly ,lived in
is the sudden sw1tchmgon
î
a{' a «
_______…______: