Do tench fish change colour?

[camillavic]

Hi People

Does anybody know if tenches change colour? I have 7 in my pond, 5 orange and 2 half white/half orange and 2 sturgeons. But i today discovered 3 new little black fish and am totally confused. The only logic i could come up with is that maybe they change colour but i am hoping that somebody will know for sure.
Also, most of my plants in the pond die in the winter and come back in the summer and im a bit worried about not having enough oxygen in the pond so any advice on plants that lasts through a winter on the British South Coast?

Thanks for any advice!
Camillavic

 

[macky1]

colder water contains a higher amount of dissolved oxygen
so dont worry about the oxygen levels they should be fine

p.s
dont have your waterfall or fountail running in winter
the surface of the water must be still

 

[camillavic]

Thanks for advice Macky,
didnt know i should turn waterfall off, thought the water would freeze!

 

[macky1]

the water could well freeze but make show u put a hole in the ice by placing
a pan of hot water on the ice for 5 mins or so too melt a hole so the gases which are toxic to fish can escape
DO NOT smash a hole in the ice as this will stress the fish

im still learning me self so im open to any other ideas but this is what i have been advised to do by books,L.F.S and freinds

hope this helps

macky

 

[Death Penguin]

I presume there must be more than one type of Tench? Just that when I used to go fishing, the main attraction was to catch Tench. Awesome powerful fish!!!! .
They used to be dark green in colour, but i suppose, that if you are keeping them for a hobby then they aren't the common variety?