Iridescent Shark

Question
My large (5") Iridescent has developed a spot behind each of its pectoral fins. They're light yellowish.  Is this Ich or some type of fungus?  Tank-40 gals. 2 other IS, 3 siver dollar Barbs and one Tricolor shark show no signs.  Tri & 2 IS were added 1 week ago. Temp=82F. I have a PIC of the shark & spot if there's a way to send it.
Thanks,
Sal

Answer
I would suspect a fungus. Ick would look like salt and it would be all over the fishes body. Also, it would be very contagious and the other fish would have signs. And, ick has a very hard time surviving at temps above 80. Its a good thing you keep your tank at 82, as ick almost never appears at this temp. I would say its a fungus and it should be treated. Is the fish eating still and swimming good? If there are no signs but the spots I would treat. Follow the directions exactly including the water changes. Once you have treated the fish once, one cycle, do a large water change around 45-50% to remove the excess treatment. Also, be sure to find out if the treatment requires removing the filter or not. Either way, replace the filter cartridge after you treat. Treat one cycle, if the spots are still there treat again after the large water change. Try not to stress the fish out too much with the water changes. I hope this helps. Let me know if you need more help or have more questions.