Orthoprotella, Mayer, 1903

Lim, Jacqueline Hui Chern, Othman, Bin Haji Ross & Takeuchi, Ichiro, 2015, Description of Orthoprotella bicornis, new species, and Paraprotella teluksuang, new species (Crustacea: Amphipoda) from Johor, Malaysia with special reference to unusual sexual bias towards females in Paraprotella, Raffles Bulletin of Zoology 63, pp. 33-48 : 41

Key to the species in the genus Orthoprotella

( Orthoprotella melloi Quitete, 1975 and O. hamata Arimoto, 1981 are omitted from this key.)

– Body dorsally smooth.............................................. GROUP 1

– Body provided with dorsal projection..................... GROUP 2

GROUP 1

1. Pereonites 2–3 with 1 anterolateral projection....................... 2

– Pereonites 2–3 without anterolateral projection....................... ................................. Orthoprotella tasmaniensis Guiler, 1954

2. Pereonite 4 with 1 anterolateral projection ............................3

– Pereonite 4 without anterolateral projection............................. .......................................................... O. mayeri Barnard, 1916

3. Pereopods 3 and 4 with 1 article.............................................. ................................................ O. pearce Guerra-García, 2006

– Pereopods 3 and 4 with more than 1 article (2-articulate)...... ................................... O. berentsae Takeuchi & Lowry, 2007

GROUP 2

1. Head with 1 large dorsal projection or 1 small dorsal hump.. ................................................................................................. 2

– Head with 1 pair of dorsal projections................................... 4

2. Body very small (length <3 mm); Antenna 1 short, about 2/3 whole body length..................... O. nana Guerra-García, 2004

– Body large (length> 10 mm); Antenna 1 long, about 5/6 whole body length.............................................................................. 3

3. Pereonite 1 without dorsal projection....................................... ........................................................... O. gordoni Guiler, 1954

– Pereonite 1 with 1 acute dorsal projection............................... .................... O. tuberculata Guerra-García & Takeuchi, 2004

4. Pereonites 2–3 with 1 pair of anteriorly curved mid-dorsal projections ......................................... O. spinigera Mori, 1996

– Pereonites 2–3 without mid-dorsal projections...................... 5

5. Antenna 1 peduncular article 3 provided with several projections anterodistally ..................................... O. bicornis , new species

– Antenna 1 peduncular article 3 without projections anterodistally .............................. O. australis ( Haswell, 1880)