Hemigaleidae

White, William T. & Harris, Mark, 2013, Redescription of Paragaleus tengi (Chen, 1963) (Carcharhiniformes: Hemigaleidae) and first record of Paragaleus randalli Compagno, Krupp & Carpenter, 1996 from the western North Pacific, Zootaxa 3752 (1), pp. 172-184 : 182

Key to the species of Hemigaleidae from the western North Pacific (adapted from Compagno, 1998)

1. Lower teeth near symphysis with long, strongly hooked cusps that prominently protrude from mouth when closed; gill slits large, usually more than twice eye length................................................................... 2

- Lower teeth near symphysis with short, straight or weakly hooked cusps that are mostly concealed when mouth is closed; gill slits small, less than twice eye length...................................................................... 3

2. Snout obtusely wedge-shaped in ventral view; fins not falcate, with posterior margins of paired fins straight to slightly concave; teeth present at symphysis of lower jaw.......................... Chaenogaleus macrostoma (Indo–West Pacific)

- Snout bluntly rounded in ventral view; fins strongly falcate, with posterior margins of paired fins deeply concave; teeth absent at symphysis of lower jaw.............................................. Hemipristis elongata (Indo–West Pacific)

3. Lower teeth near symphysis with erect cusps and highly arched roots giving them an inverted Y-shape; no cusplets on lower teeth; mouth very short and broadly arched; pelvic, both dorsal and lower caudal fins strongly falcate..................................................................................... Hemigaleus microstoma (Indo–West Pacific)

- Lower teeth near symphysis with mostly erect cusps and slightly arched roots giving them an inverted T-shape; cusplets present on lower teeth; mouth longer and narrowly arched; pelvic, dorsal and caudal fins not falcate....................... 4

4. 5 or more rows of lower anterolateral teeth with distal cusplets; lower anterior teeth mostly with oblique cusps; a pair of longitudinal black lines on underside of prenarial snout; total vertebrae 164–187........ Paragaleus randalli (Indo–West Pacific)

- 2 or 3 rows of lower anterolateral teeth with distal cusplets; lower anterior teeth mostly with erect cusps; no black lines on underside of prenarial snout; total vertebrae 127–135........................ Paragaleus tengi (western North Pacific)