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o
6
.
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«
2 Th€'AŒ1&ÏIÇ‘EËŸËËËËËÊ
,
eñvir0nmentin which fish live in captivity is made up
of a very
’
zi"
Z complicated mixture of various factors — physiCal, chemical, and
,
—
covering many areas of knowledge, Of these factors
[
only the less complex ones are usually under the direct control Of
_
the aquarist, and by judicious manipulation of these he can often. "
_
compensate for his inability' to “adjust in other directions. An unsuit—
-
able .envir0nment ? quickly &… the difficulties which are
the basic situation of containing afish in a relatively
,
.
small Volume of water, "Whereàs correct and knowledgeable treat—
’
_jrent will assist
fish in adapting to the rather unnatural con—
-
‘L_
7“
ditions inWhichit finds itself;
The fishes themselVeS
many-and varied and may come from
'
quite different parts of the world and yet, in the case of the usual
aquarium community, they a”œexpeCted to live together peacefully
_
"
happi_l‘y; Their individual requirements may vary in the extreme
__
.
but there are f0rtunatdy,mzinybaSic factors which are common to ‘
…' almost all specieë._ —
_
…
_
_
'
‘
…
Fish can be diÿided intocategories and classified in terms of the
.
-
envir0nmental factors which form the” most noticeable differences in
-
their ways of life'4'Eor example“,
speciesmay be described
‘
as
being
tropical” rather than cold—
.
water, livebearing‘ratherthan egglaying,and soon. By sign'posting its
.
‘
environmental
characteristic—s in this way we immédiat—<
ely knOW' what sort of fish it is and
its
will be whenkept in captivity.
to emphasi'sèiä
that
essential to establish-an?environment“which is tailored toraw
particular type Of ShÂ_ÏŒÎ
«Organisms if the
encourage them ' t0- dlSplayor*carry… Out that
;of
life whichhe most w1shestostudy
1
.
_
…=…:f…._— ÿFigur€ 1 illustrates£ diagrammaticallythe maj
types of
,
€nVif0nment- Th€ Pf1nCIPa1fætorsmeach Ïc‘>£ the. four
‘
sectorsof