Key to Adult Male New Zealand Coastal Talitroid Species

1. Gnathopod 1 with palmate lobe on propodus only........................................................... 2

- Gnathopod 1 with palmate lobe on merus, carpus and propodus................................................ 4

- Gnathopod 1 with palmate lobe on carpus and propodus...................................................... 5

2. Gnathopod 2 palm extremely acute........................................... Tatahipeke tumida (Stebbing, 1887)

- Gnathopod 2 palm not extremely acute.................................................................... 3

3. Gnathopod 1 subchelate. Gnathopod 2 propodus without palmar sinus....... Bellorchestia quoyana (Milne Edwards, 1840)

- Gnathopod 1 parachelate. Gnathopod 2 propodus with small distal palmar sinus....... Bellorchestia spadix (Hurley, 1956)

4. Gnathopod 2 propodus palm nearly transverse, evenly rounded; dactylus with slight posteroproximal projection. Pereopod 6 carpus subovate........................................................ Transorchestia miranda Chilton, 1916

- Gnathopod 2 propodus palm acute, concave; dactylus posterior margin smooth. Pereopod 6 carpus subrectangular............................................................................. Transorchestia serrulata (Dana, 1852a)

5. Pereopod 7 sexually dimorphic, with basis, merus or carpus greatly enlarged...................................... 6

- Pereopod 7 not sexually dimorphic, with basis, merus or carpus slender, rectilinear................................. 8

6. Antenna 1 short, not reaching midpoint of peduncular article 5 of antenna 2. Gnathopod 2 palm extremely acute.................................................................................... Tatahipeke cookii (Filhol, 1885)

- Antenna 1 long, reaching midpoint of peduncular article 5 of antenna 2.......................................... 7

7. Gnathopod 2 propodus with midpalmar and proximal sinuses. Pereopod 7 carpus enlarged, rounded................................................................................... Aotearorchestia chathamensis (Hurley, 1956)

- Gnathopod 2 propodus without palmar sinuses. Pereopod 7 carpus enlarged, subovate............................................................................................... Aotearorchestia telluris (Spence Bate, 1862)

8. Uropods 1 and 2 endopods with marginal setae in two rows........ Subantarctorchestia aucklandiae (Spence Bate, 1862)

- Uropods 1 and 2 endopods with marginal setae in one row.................................................... 9

9. Gnathopod 1 palm angle transverse................................... Subantarctorchestia bollonsi (Chilton, 1909)

- Gnathopod 1 palm angle obtuse................................................ Tatahipeke kirki (Hurley, 1956)