Key to the Indo-West Pacific species of Palaemonella
1. Supraorbital tooth present............................................................................... 2
- Supraorbital tooth absent................................................................................ 6
2. Ischia of second pereopods each with distoventral tooth.................................... P. crosnieri Bruce, 1978
- Ischia of second pereopods without distoventral tooth......................................................... 3
3. Postorbital ridge on carapace distinct...................................................................... 4
- Postorbital ridge on carapace obscure or absent.............................................................. 5
4. Dactyli of third to fifth pereopods long, slender, about 9–11 times as long as basal width..... P. longidactylus Hayashi, 2009
- Dactyli of third to fifth pereopods relatively short and moderately slender, 4.6–6.0 times as long as basal width............................................................................................ P. spinulata Yokoya, 1936
5. Rostrum as long as or longer than carapace.............................................. P. dijonesae Bruce, 2010
- Rostrum shorter than carapace.......................................................... P. maziwi Bruce, 2002
6. Dactyli of third to fifth pereopods slender, more than 8.0 times longer than basal width.............................. 7
- Ambulatory dactyli moderately slender, less than 8.0 times longer than basal width................................ 12
7. Hepatic tooth in branchiostegal position.................................................................... 8
- Hepatic tooth not in branchiostegal position................................................................ 10
8. Carapace with distinct postorbital carina, posteriormost tooth of dorsal rostral series located at about 0.3 of carapace length...................................................................................................... 9
- Carapace without postorbital carina, posteriormost tooth of dorsal rostral series located at 0.25 of carapace length........................................................................................... P. meteorae Bruce, 2008
9. Carapace with large antennal tooth.................................................. P. k o m a ii Li & Bruce, 2006
- Carapace with small antennal tooth............................. Palaemonella sp. sensu Li, Mitsuhashi & Chan, 2008
10. Propodi of third to fifth pereopods subdivided, each with ventral spinules................. P. dolichodactylus Bruce, 1991
- Propodi of third to fifth pereopods not subdivided, without ventral spinules....................................... 11
11. Chela of second pereopod with fingers shorter than palm; dactylus of third pereopod 0.4 times as long as propodus................................................................................ Palaemonella sp. sensu Bruce, 2003
- Chela of second pereopod with fingers longer than palm; dactylus of third pereopod 0.2 times as long as propodus.......................................................................................... P. h a c h ij o Okuno, 1999
12. Merus of second pereopod without conspicuous tooth at ventrolateral distal angle.................................. 13
- Merus of second pereopod with conspicuous tooth at ventrolateral distal angle.................................... 17
13. Carapace with distinct postorbital ridge........................................................ P. okunoi n. sp.
- Carapace without postorbital ridge....................................................................... 14
14. Carapace with 3 postrostral teeth, of which 2 located posterior to level of hepatic tooth.............. P. aliska Marin, 2008
- Carapace with 1 or 2 postrostral teeth, of which only 1 or none located posterior to level of hepatic tooth............... 15
15. Carpus of second pereopod with 2 conspicuous distomesial teeth................................. P. lata Kemp, 1922
- Carpus of second pereopod unarmed on distomesial margin................................................... 16
16. Rostrum not reaching distal end of antennular peduncle, with 6 dorsal (including 1 postrostral) and 1 ventral teeth; eye with cornea not wider than eyestalk, eyestalk not narrowing proximally.............................. P. pusilla Bruce, 1975
- Rostrum overreaching distal end of antennular peduncle, with 8 dorsal (including 2 postrostral) and 2 ventral teeth; eye with cornea wider than eyestalk, eyestalk distinctly narrowing proximally.......................... P. burnsi Holthuis, 1973
17. Distoventral tooth on carpus of second pereopod distinctly subterminal......................... P. tenuipes Dana, 1852
- Distoventral tooth on carpus of second pereopod terminal..................................................... 18
18. Postorbital ridge on carapace distinct; dorsal rostral teeth moderately stout, not markedly curved..................... 19
- Postorbital ridge on carapace absent; dorsal rostral teeth slender, curved........................... P. foresti Bruce, 2002
19. Dactyli of third to fifth pereopods each with flexor margin ventrally concave; flexor distal spines on propodi long, about 0.5 of dactylus length................................................................ P. ro t u m a n a (Borradaile, 1898)
- Dactyli of third to fifth pereopods each with flexor margin sinuous or biconcave; flexor distal spines on propodi short, about 0.25 of dactylus.................................................................. P. pottsi (Borradaile, 1915)