A Lump Beneath The Flowerhorn Belly

My flowerhorn develop a lump under his belly.

Can anyone tell me what is it?



Thanks

This looks as though it could be caused by parasites, but we need some more information.

How big is the tank and what else is in it? If you're keeping flowerhorn I'm going to assume that the water stats are perfect, but if I'm wrong please correct me.

What do you feed him? How much and how often? Has this changed recently? Does he get live food like tubifex from a wild source or live feeder fish?

What does his poo look like? Is it normal?

I agree need more info.
Size of tank in gallons or litres.
How many fish and which type.
Water stats in ammonia, nitrite, nitrate, and ph.
Is the fish flicking and rubbing itself on things in the tank.
Any excess mucas on the gills or body of the fish.
Has the lump just suddenly appeared.

It looks like your fish has a prolapsed rectum most likely caused by an internal protozoal infection. A good internal protozoal med/medicated food and a diet high in fiber could clear this up but it will take time. Have a google at 'Flowerhorn prolapsed rectum' for a more specific list of meds available in your area.