I recently ordered fish online from aqua huna. I have ordered from them before with no issues. This time around I got 20 kuhli loaches. They came in 2 separate bags of 10. Each bag had at least one fish with what appears to be a fungal infection. I got all of the fish out and put them in my quarantine tank and now they are in there. My question is what is this, what caused it, and how do I cure it? Also how contagious is it? Thank you all in advance for your help!