They borrow their name from the Greek oreos (mountain) and somas (backs) for the shape of their backs. They are very flattened vertically-laterally, with 5 to 8 rays in their dorsal fin, and 2 to 4 in the anal fin, and only 1 spine in the pelvic fins.
These fish get their name from Greek words oreos (mountains) and somas (backs), mirroring the shape of their backs. They have a flattened profile, with 5 to 8 rays in their dorsal fin, 2 to 4 in the anal fin, and just one spine in the pelvic fins.