Common
carp


indicate


that


Koi


are


of


the


East


Asian
subspecies.

However


another


recent


study


on

the
mitochondrial

DNA

of


Koi


have

found


that


Koi


are
descended

from

multiple


lineages


of


common


carp


from
both

Western


Eurasian


and

East


Asian


varieties.
"Discovery
of


an

ancient


lineage


of


Cyprinus


carpio


from
Lake
Biwa,


Central


Japan,


based


on

mtDNA

sequence
data,

with


reference


to


possible

multiple


origins


of


Koi.
This

could


be

the


result


of


Koi


being


bred


from

a

mix

of
East

Asian


and

Western


Eurasian


carp


varieties,


or


Koi
being

bred


exclusively


from

East


Asian


varieties


and
being

subsequently


hybridized
with

Western


Eurasian


varieties.
The

Butterfly

Koi


is


one

known
product

of


such

a

cross.
Keeping

KOI


-


The


common
carp

is


a

hardy


fish,


and

Koi
retain

that


durability.


Koi


are
cold
-

water


fish,


but


benefit


from
being

kept


in


the


59

-


77
degrees
F

range

and

do

not
react

well


to


long


cold


winter
temperatures,

their


immune
system
'turns


off'


below

50
degrees
F.


Koi


ponds


usually
have
a

meter

or


more


of


depth


in


areas


of


the


world


that


become

warm


during


the


summer,


whereas


in


areas
that

have

harsher


winters,


ponds


generally

have

a

minimum

of


4

1/2


feet.


Specific


pond


construction


has
evolved

by

Koi


keepers

intent


on

raising


show


quality


Koi.
The

Koi’s

bright


colors

put


them

at


a

severe


disadvantage
against

predators;


a

white

-

skinned


''Kohaku''


is


a

visual
dinner

bell

against


the


dark


green

of


a

pond.


Herons,
kingfishers,
raccoons,


cats,


foxes,


Badgers


and
hedgehogs

are


all


capable


of


emptying

a

pond


of


its

fish.
A
well

-

designed

outdoor


pond


will


have

areas


too


deep
for

herons

to


stand


in,

overhangs

high


enough


above


the
water

that


mammals


can't


reach


in,

and

shade


trees