Key to species of Grandidierella in the South China Sea (adult males)

1. Uropod 1 peduncle lacking inter-ramal process ................ G. melakaensis Azman & Othman, 2012

– Uropod 1 peduncle with inter-ramal process .................................................................................... 2

2. Coxa 2 with posteromedial projection .............................................................................................. 3

– Coxa 2 without posteromedial projection ......................................................................................... 4

3. Gnathopod 1 basis slender (length ca 3.3 times of width) .................................................................. ............................................................ G. halophilus Wongkamhaeng, Pholpunthin & Azman, 2012

– Gnathopod 1 basis wide (length ca 2.0 times of width) ..................................................................... ........................................................... G. phetraensis Wongkamhaeng, Coleman, Pholpunthin, 2013

4. Gnathopod 1 carpus with stridulating ridges ............................................ G. vietnamica Dang, 1968

– Gnathopod 1 carpus without stridulating ridges ............................................................................... 5

5. Gnathopod 2 basis anterior margin with crenulation ...................................... G. pawaiensis sp. nov.

– Gnathopod 2 basis anterior margin without crenulation ................................................................... 6

6. Gnathopod 1 propodus with apical acute process ........................................... G. sungeicina sp. nov.

– Gnathopod 1 propodus without apical acute process ..................................... G. gilesi Chilton, 1921