Corydoras with small eye

[Terry Ellacott]

I have a colony of Corydoras metae which is over 25 years old which must be very in bred by now. I am getting healthy strong fish but occasionally I have a fish with an eye with a reduced iris. The photos I have taken are of the same fish with one normal eye and one reduced. If anyone knows anything about this I would be very interested to know more. 

[Daniel]

I think maybe he just took too many of his prescription pain meds.🙂

[FrostiesFishes]

I have no insight to this but am also super curious. How often do you see the small eye happen and is it both eyes or just one? 

[Terry Ellacott]

This fish has only one small eye. The first photo is of the same fish that is in the foreground of the second photo. I have other fish with the small eye but it does not show up as much because they lack the gold ring in the eye, their eyes are more uniform black. I've been looking this morning and ones I have noticed have one eye affected. The percentage of fish with the small eye is low, 5% or less. 

 

 

[FrostiesFishes]

Interesting it May just have something to do with your genetics in the colony, I know that some university has been working with carp or crappie for like 50 years and they don’t show any significant inbreeding traits  

[Terry Ellacott]

I've just checked and found that I bought six fish in 1998.I bred quite a lot of them for about eight years during which I selected the breeders mostly for big black fins.For the last ten years they have been left to get on with it and have gone down hill a bit.Over the last two weeks I've filled them full of white worms and collected about 30 eggs,I'll grow them on and pick the best to continue the colony.