deformed ventrals

[Corie Dora]

I have a batch of around 60 cacatuoides juvies, and it appears that nearly all of them have deformed ventrals. Some are missing them entirely, some are missing just one, and most of them have one or two deformed stubby little ventrals. Other than that these fish are doing great, and are large and healthy for their age, and beginning to show sexual differences.

Is this type of deformity likely to be genetic, or caused by some kind of bacterial infection?

 

[Nick S.]

Deformed

It could be caused by inbreeding, I have seen fish that someone was breeding for 4 or 5 generations from the original pair, that were deformed had stunted fins and other things wrong with them.

 

[Corie Dora]

That's the weird thing....the female was a second gen. fish from a really clean line I purchased from another hobbyist. I'd never seen any problems in the fry I had previously, though I didn't raise them very intensively.

The male, I bought at a shop and had come straight out of singapore. I figured I'd do good adding some new blood....perhaps he was so inbred my plan backfired.

 

[ed seeley]

As it appears you are performing an outcross here and it is surprising to see the deformities I would probably let the pair produce another brood, but make sure the tank is scrupiously clean and the babies get a good, constant food source so that hasn't caused the problem. Be prepared though, if the deformity shows up again to cull the entire brood and then split up the parents.
It's strange that crossing two, seemingly unrelated, lines has produced this, but it's not impossible. Maybe swap the male for one of a thrid different strain and see what happens there?

 

[Refael Hdr.]

Is it the only deformation you can spot?
Does the general shape look fine? Can you notice any skeleton deformations?...

 

[Corie Dora]

Well, unfortunately I've lost the male since the spawning, so letting the pair produce again is out of the question. The female was sick for a while as well (this all occured 8 weeks after spawning and 4 weeks after separation from the young) and has now been treated. She's nearly 3 yrs old, so I'm not sure that she'll spawn again anyhow. My original plan was to cross a male youngster back to the mother, as I really liked the looks of her father, and knew the line was clean.

I'm just wondering if I should try and breed any of them now.

The general shape is excellent. This is definately the only problem at all. As I mentioned before, they are large for their age, robust and are already colouring nicely and showing good finnage.