Gastroptychus, Caullery, 1896

Ahyong, Shane T. & Poore, Gary C. B., 2004, The Chirostylidae of southern Australia (Crustacea: Decapoda: Anomura), Zootaxa 436 (1), pp. 1-88 : 7

Key to Indo­West Pacific species of Gastroptychus

1 Rostrum with two pairs of lateral spines....................................... G. spinirostris n. sp.

— Rostrum without lateral spines...................................................................................... 2

2 Abdomen without transverse rows of spines or spinules on somites 2–5..................... 3

— Abdomen with transverse rows of spines or spinules on somites 2–5 .......................... 9

3 Propodus short, about 0.15–0.20 carpus length ............................................................ 4

— Propodus as long as or longer than carpus…. ............................................................... 5

4 Abdomen with dorsal spines ....................................... G. novaezealandiae Baba, 1974

— Abdomen without dorsal spines ..................................... G. brevipropodus Baba, 1991

5 Propodus of walking legs smooth, extensor margin without spines, with 2 or 3 movable spines on distal flexor margin................................... G. laevis ( Henderson, 1885)

— Propodus of walking legs with spines along extensor margin and more than 10 movable spines on flexor margin ......................................................................................... 6

6 Carapace ovate, broader than long (excluding rostrum) .............. G. chacei Baba, 1986

— Carapace subquadrate, distinctly longer than broad (excluding rostrum)..................... 7

7 Carapace with numerous spinules covering surface of carapace .................................. 8

— Carapace with paired epigastric spines, median and lateral longitudinal row of 2–4 spines, but without numerous spinules covering surface of carapace. Ventral surface of sternum without transverse rows of spinules ....................... G. paucispina Baba, 1991

8 Abdominal somite 6 with spines on proximal dorsal surface ......................................... ............................................................................................... G. valdiviae ( Balss, 1913)

— Abdominal somite 6 without spines on proximal dorsal surface .................................... ............................................................................... G. sternoornatus ( van Dam, 1933)

9 Rostrum with 2 dorsal spines; distinctly longer than half carapace length (excluding rostrum) ............................................................................ G.ciliatus ( van Dam, 1933)

— Rostrum shorter than half remaining carapace length; without dorsal spines............. 10

10 Anterior half of carapace without spines along midline ..... G. hawaiiensis Baba, 1977

— Anterior half of carapace with 1–3 spines along midline............................................ 11

11 Abdominal somite 3 without spines or spinules.............................................................. ............................................................. G. investigatoris (Alcock & Anderson, 1899)

— Abdominal somite 3 with spines, at least on pleura.................................................... 12

12 Tergite of abdominal somite 3 not spinose; with weak spinules on pleura. Propodus and carpus of third maxilliped without spines on extensor margin................................. .................................................................. G. hendersoni (Alcock & Anderson, 1899)

— Tergite and pleura of abdominal somite 3 strongly spinose. Propodus and carpus of third maxilliped with spines on extensor margin ......................... G. rogeri Baba, 2000