Deformities in tilapia
In fish farming it's important to think about the end user. If your fish are going to be fileted before the consumer sees them there is likely to be no problem. However if you are selling to restaurants which serve whole fish, you need to be producing not only heavy fish but also attractive ones. The consumer, doesn't want to know about what goes on at a fish farm just as they don't want to know where their beef, pork, chicken or lamb comes from.
The truth is in fish farming you get fish with deformities. It isn't that there is anything wrong with the quality but visually this could be a problem for the unsuspecting public.
So what causes this to happen?
When you buy multiple fish from a breeder it is likely you will have some with deformities due to breeding conditions, such as over crowding or even injuries which didn't heal correctly.
We noticed fish which had eyes missing. This could have happened due to the intensive breeding conditions.
We also had some which appeared to be a birth defect. This was evident in the lack of a dorsal fin. Perhaps, given a high volume of fish, there will always be this anomaly. If you are new to fish farming or farming in general, this can be quite disturbing to see. I can't say this impeded the development of these fish as they ate and swam as well as the others.
For us it didn't affect the value of our fish as we sold them by the kilo. If these were sold to restaurants, it could be that they would take only fish without any obvious abnormalities if they were to be served to their clients as whole fish.
Another thing I would like to mention here is specific to keeping fish in cages. The fish although they know they are caged, will swim into the sides. This leads to red mouths or contusions. This too doesn't affect resale value if selling by the kilo but yet again, doesn't look correct when eating at a restaurant.