I think the colorful fish with the piranha teeth that chip00 refers to is a parrot fish, which eats coral. I do not know the Spanish term and I can hardly beleive they would be tasty.
Steve
Yes Steve I believe you're right the Stoplight Parrotfish (Sparisoma viride) is what I believe that it is. However, it is not that bad and is a staple fish here and in Puerto Rice from the web research I've done. I was looking to eat fish today and saw it on two restaurant's different menus.
Also, it's sold at a series of fish camps on the highway from Santriago to Puerto Plata near Imbert - this is where all of the locals talk about going. The prices aren't that bad either. I recommend the mero bien frito which with the sides and a drink comes out to about $150.
Also, there is a great, inexpensive seafood restaurant in Puerto Plata on the left side if your heading north on the Malecon right before you get to the last turnoff on the left - if you go straicght you end up at a dead end at the park. It doesn't look a whole lot like much - I remember they have like a thatched roof and use a plastic tarp when it rains but they have some of the best damn seafood I've ever eaten - and I grew up in Charkeston, SC - no slouch when it comes to reputation for good seaford. I think the name has "Hermanos" or "Amigos" in it. The fried mero I had was cooked crispy to perfection.