Macrocephenchelys, Fowler, 1934

Lin, James, Shao, Kwang-Tsao & Smith, David G., 2018, The eel genus Macrocephenchelys (Anguilliformes: Congridae) in Taiwan, with description of a new species, Zootaxa 4454 (1), pp. 186-199 : 198

Key to the known species of Macrocephenchelys

1a. Dorsal-fin origin well behind tip of pectoral fin, by a distance greater than pectoral-fin length; head short, less than 10%TL; ST pore present; no fleshy papillae on head; no sensory pits on abdomen; vertebrae more than 170.............. M. brachialis

1b. Dorsal-fin origin over pectoral fin or slightly behind, by a distance of less than pectoral-fin length; head longer, more than 10%TL; ST pore absent; fleshy papillae on head and sensory pores on abdomen present; vertebrae fewer than 160....... 2

2a. Dorsal-fin origin over middle of pectoral fin................................................. M. soela (Australia)

2b. Dorsal-fin origin over or slightly behind tip of pectoral fin.....................................................3

3a. Bicolored, gray above and white below, without a patch of pigment around anus and on abdomen; PAL 27–34%TL; vertebrae 147–154................................................................................. M. brevirostris

3b. Bicolored but with a conspicuous patch of pigment around anus and on abdomen; PAL 24–28%TL; vertebrae 125–135....................................................................................... M. nigriventris sp. nov.