Catfish shark about to die

[Andywan]

I have two Columbian catfish sharks and one is acting strange kinda lathargic, and I noticed two indentions under the dorsal fin. Perameters are all normal..no changes made to the tank. Is he messed up with something ..none of the community are aggressive. https://www.dropbox.com/s/0bs9i2zk9q0c8y5/20190122_182313.jpg?dl=0 https://www.dropbox.com/s/7gs307jqe7ljj5o/20190122_182316.jpg?dl=0 https://www.dropbox.com/s/ukpuza8zbq5mf52/20190122_182322.jpg?dl=0 thanks for advice.

 

[Colin_T]

I can't tell anything from those images. If you can post an image that clearly shows the problem we might have more to go on.

The best thing to do if fish are acting weird is check the water quality and do water changes and gravel cleaning. Do a 75% water change and gravel clean the substrate every day for a week. Make sure any new water is free of chlorine/ chloramine before it is added to the tank.