Contact a local veterinary clinic or hospital.

Dear David

many thanks for the suggestion, but the fish specimens should be available first.

Its available in Indian waters?

We are doing X-rays of Fishes in normal  digital medical X-rays, only thing is the Technician should be perfect in doing X-rays of small bones. Please try at your native place, I hope it can be done properly.

I agree with Dr A. David Scarfe. That's what I did personally.

Dear All

I know very well how to get an an x-ray and from where, but I would like to hear from people from the countries that I mentioned to supply x-rays for Zeus faber from their countries specifically.

http://naturalhistory.si.edu/exhibits/x-ray-vision/x-ray-technique.cfm

https://anmm.wordpress.com/2015/10/26/how-do-you-x-ray-a-fish-inside-the-smithsonians-national-collection-of-fishes/

This site very useful for you

The x-rays that pass through the three Lookdown specimens are captured on a digital detector, which produces an image that makes the specimen appear transparent: bone is white, and soft tissue is grayish-black. The x-rays in this exhibit were taken at exposures of 30 to 70 kilovolts for 5 to 10 seconds, depending on the size and density of the fish.

Sorry Majid

My problem is not with x-ray machine, but I need fish samples of the species Zeus faber from the following countries;

Brazil, Uruguay, Argentina, Chile, Peru, Ecuador, Namibia, Congo, New Caledonia, Fiji, and Papua New Guinea

Sorry Dear jawed ...so maybe usful to other researchers 

Regards