Mephisto spikefishes have six spines in the dorsal fin, these gradually decrease in size from the front to the rear but the rearmost spine is still clearly visible. They have a snout which is shorter than the length of the remainder of the head and which is nearlyequal to the between the eye and the upper end of the gill slit. They have a single row of large and conical teeth in each jaw. These fishes have the longest gill slts of their family, the lower margin of the slit reaches slightly below the lower margin of the lobe at the base of the pectoral fin. M. albomaculosus is knowm from its holotype which had a standard length of, while M. fraserbrunneri has a maximum publishedstandard length of.
Distribution and habitat
Mephisto spikefishes have been recorded from the IndianOcean from off Somalia east to off Myanmar at depths between.