Tang Teeth???

[fredro]

So I have 2 tangs in my tank. A Yellow Tang and a Two Spot Bristletooth Tang (Blue Eyed Kole Tang). The 2 Spot is a juvenile. Both fish LOVE Nori. The Yellow Tang comes up to the clip and bites of pieces of it aggressively and leaves little half-circle, bite marks in the remaining Nori. The 2 Spot, in the other hand, seems to not have anything abrasive on or around his mouth, which results in the fish slobbering and lipping at the Nori, but unable to bite it off. Eventually pieces get broken down and pulled off, but for a fish named for its "Bristletooth," I would expect there to be more bites taken out like the yellow tang. Is this normal or could it be that the fish is a juvenile (~3") and hasn't fully developed its mouth or whatever it is that it uses to bite off vegetation? It seems like in the wild, it would starve, if left to graze.

Any info would be much appreciated.

 

[BAD FISH]

I don't know about the "tooth development" lol but I know they sometimes loose teeth or break them because they are flexible teeth. Or the mouth could have been damaged in the capture and/ or transport of the fish. It happens with wrasses alot, when they try to burrow during shipping and keep smacking the bottom of the bag or box. They break their own jaws.

 

[Jhoehlein]

Two different mouths for two different methods of feeding. Yellow tangs are nippers, bristletooth tangs are scrapers.

Yellow tangs, like all of the Zebrasoma tangs, have a small narrow mouth on the end of a snout. Perfect for taking small nips out of macroalgae, or reaching into crevices other grazers can't get into.

Ctenochaetus tangs, the Bristletooth tangs, have big floppy mouths with lots of surface area. Mush that big mouth onto a rock, use those bristle teeth to scrape off whatever might be growing on it, move on to the next spot. Great for scraping wide swaths of rock for microalgae and diatoms, but not really delicate enough to handle taking discreet nibbles from a flexible, flowing in the current macroalgae. Better to let the nippers rip it up first, then chase down the easily swallowed bits.

 

[fredro]

Makes perfect sense. I just feel so bad for the little guy as he sits there trying to suck the pieces off the clip, and not getting much. He's still fat as all hell tho... So it can't be any more than frustrating for him.