I saw several pairs of these fish. They look like a type of razorfish, but I havent' been able to positively ID them. They were around 2" long and located in 50 feet of water. The fish would glide over the bottom and disappeared in the sand if I got too close. The location is the northern Gulf of Mexico. The bottom consists of sand and an artificial reef made of concrete culverts.
Note: I've seen a few adult Pearly razorfish in this part of the Gulf, but these fish were smaller. I don't know if they are young Pearly razorfish or something else.
Sorry about the blurry photos, but they were hard to approach and difficult to focus on.