Tangs with internal parasites?

[kingkai512]

I Have 2 tangs that are very thin even with the amount of feeding I do. The yellow tang i have had for 6 months and he has never gotten fatter. He has always been very thin and almost skeletal.

Now my hippo tang is starting to look a bit thin with a pinched stomach. Both are not aggressive eaters and have never been, the angels in my tank eat all the greens before they can get more than 3 bites in. The angels are all fat and healthy but its just these two non aggressive eaters that are concerning me...
So what can i do? Is it internal parasites thats not causing them to gain weight? How can i feed them a supple amount before the angels engulf everything if they wont eat aggressively?

 

[GrandmaRaff]

Your tangs need Nori. Go to your local Asian market and purchase a package of Nori. Then take a sheet, fold it several times and rubber band it to a rock. Give it about 30 minutes and you won't see pinched bellies anymore as they will devour that sheet of Nori.

 

[Zionas]

Malnutrition. Second the need for nori.