[1] When he described M. fraserbrunneri Tyler gave its type locality as the Bay of Bengal at 10°39'N, 97°06'E from a depth of 159 fathoms (954 ft; 291 m).

[2] In 1968 James C. Tyler classified this genus in the nominate subfamily of the family Triacanthodidae, the Triacanthodinae.

[3] The 5th edition of Fishes of the World classifies the family Triacanthodidae in the suborder Triacanthoidei in the order Tetraodontiformes.

They have a snout which is shorter than the length of the remainder of the head and which is nearly equal to the between the eye and the upper end of the gill slit.

[7] Mephisto spikefishes have been recorded from the Indian Ocean from off Somalia east to off Myanmar at depths between 74 and 446 m (243 and 1,463 ft).