The blacksaddle filefish, "Paraluteres prionurus", is a filefish of the family Monacanthidae. There are pictures of the Smooth Hammerhead, Cutlassfish, slender filefish, Serranidae, and Cirripedia. Commonly consumed fish include menhaden, eels, silversides, wrasses, jacks, toadfish, and filefish. The planehead filefish can be used for human consumption. In the Canary Islands the growth and ageing of the planehead filefish have been studied. The young filefish are pelagic; that is, they frequent open water. Scientific examination of blue marlin stomach contents has yielded organisms as small as miniature filefish. The fringed filefish can change its colour rapidly to match its surroundings. The adult thread-sail filefish usually reside near the seabed, where the depth is around . The filefish family comprises approximately 102 species in 27 genera. The planehead filefish is found in the Atlantic Ocean at depths of up to . Filefish have rough non-overlapping scales with small spikes, which is why they are called filefish. Some filefish appear scaleless because their scales are so small. In FAO fisheries statistics, the largest category of filefish are "Cantherhines" spp. The planehead filefish grows to a maximum length of but is more typically about long.