Fish turning white

[Kris hunziker]

We have an aqua phonics system set up in the backyard with lots of fish in it. 13x 4 x 3.5 foot pond dug in the backyard with liner. We put lots of different size PVC pipe in for places to hide and have several different types of fish we caught - tilapia, blue gill, jack Dempsey - they've been in there for about 7 months and are surviving quite nicely. Recently we noticed that one of the larger tilapia (~18" in length) had turned white. We're a little worried about it. Anyone know what could cause this to happen?

[Rob Nash]

an 18 inch tilapia must be at least 3 years old.... he's at the end of his life expectancy and will die soon.. consider it grey hair... lol I would hurry up and fillet him before he goes belly up.

[Steve R]

has the temp gone down? Any other change in water chemistry? Fish will often bleach out when stressed .

[Kris hunziker]

We were figuring he was stressed out. Not sure why though. We have 2 more that are that size and they're fine. We are in SWFL and the water temp is fluctuating and we haven't put in a heater for them yet so that could be it. AND we are not sure if it's a he or a she fish. :) and we have had some babies being born but we aren't taking any of the fish out to save them. Haven't check the water chemistry, but our grow beds are giving us a bumper crop right now. We will check the chemicals to see if anything changed there.

[Keith Rowan]

where did you come up with that Rob? (18"=3years old?)

i have tilapia at 18" in around 2 years, less than optimal conditions - cool water

where have did you find the info about a 3yr life expectancy?  they can live 10-20 years in captivity!

[Randy]

Not sure if this applies to your situation, but my dominate male is white. A larger but subordinate male is more gray in color. Recently the larger male challenged the dominate one and they both were white. So if he otherwise seems health it might just be he is the dominate male.

[Kris hunziker]

And that may be part of our problem, also.  We don't know what we have when it comes to males and females.  We KNOW we have both because they've had babies.  We are assuming that at least one of the larger 3 fish is a male - he's a much lighter color and protects his little "cave" on the bottom of the pond - and his eyes are a little bulging - but he was never white like the fish was when I wrote this post.  We had thought the other two were female because they were the normal darker color - but maybe that is not the case.  

[Rob Nash]

tilapia only have a useful life expectancy of 3-5 years.. (ive never heard of 10-20yrs, where did you see that?) after that they just eat and grow very slowly, get old, get sick, and make a mess of things.. in a production system,(fish farm) they would never be in a tank more than 18 mos.. and most likely never any longer than 14-16 inches.
ask an expert! ...some one who does this for a business.

im no fish expert by any means.. ill be honest.. I don't know why they are turning white,, I just recommended they go ahead and replace the fish with some younger ones.