Gnathostenetroides, Amar, 1957

Malyutina, Marina V. & L. Bruce, Niel, 2019, The first record of Gnathostenetroididea Kussakin, 1967 from Australian waters with description of four new species of Gnathostenetroides Amar, 1957 (Crustacea: Isopoda: Asellota) from the Great Barrier Reef, Zootaxa 4554 (2), pp. 301-350 : 306

Key to the species of Gnathostenetroides

1. Body L/W ratio less than 4.5............................................................................. 2

- Body L/W ratio more than 4.5........................................................................... 4

2. Pereonite 1 longer than cephalon................................................................... G. pugio

- Pereonite 1 shorter than cephalon......................................................................... 3

3. Pleotelson shorter than wide, antennula article 1 slender........................................ G. solitaria sp. nov.

- Pleotelson longer than wide, antennula article 1 broadening distally................................ G. barringtoniana

4. Pereonite 1 as long as cephalon........................................................................... 5

- Pereonite 1 shorter than cephalon......................................................................... 6

5. Rostrum 0.3 cephalon length, 0.4 cephalon width, antennula article 1 slender...................... G. altapetra sp. nov.

- Rostrum 0.1 cephalon length, 0.3 cephalon width, antennula article 1 robust............................. G. brevicornis

6. Pereonites 4 and 5 subequal in length...................................................................... 7

- Pereonite 4 shorter than pereonite 5.................................................... G. blazewiczaei sp. nov.

7. Pereonites 2 and 3 not shorter than pereonite 1.............................................................. 9

- Pereonites 2 and 3 shorter than pereonite 1.................................................................. 8

8. Pereonites 6 and 7 longer than pereonite 5, combined length of pereonites 6 and 7 equal to pleotelson length.................................................................................................. G. renbourni sp. nov.

- Pereonites 5–7 subequal in length, combined length of pereonites 6 and 7 less than pleotelson length......... G. laodicense

9. Cephalon behind antennae as long as pereonite 1.................................................. G. samariensis

- Cephalon behind antennae longer than pereonite 1.......................................................... 10

10. Pereopod 1 slender, palm length / width> 2....................................................... G. aldabrana

- Pereopod 1 robust, palm length / width <2................................................................ 11

11. Eyes small, of 3 ommatidia, female operculum length 1.2 width........................................... G. indica

- Eyes large, of 7–8 ommatidia, female operculum length 1.6 width..................................... G. polynesica