Key to the Species of Sphagemacrurus in Taiwan

1a. Rays of V 11–14; inner GR-I 8–11; barbel length 15–24% HL; interorbital width 23–28%................................................................... S. pumiliceps

1b. Rays of V 9–11; inner GR-I 11–13; barbel length 13–16% HL; interorbital width 28–32%.................................................................... S. richardi