Key for the species identification of adult specimens of the genus Hamodactylus Holthuis, 1952 (modified from Fransen & Rauch 2013)

1. Carapace with supra-orbital tooth; dactylus of second pereiopod strongly hooked (fixed finger short, up to half length of dactylus) …………………………………………… H. boschmai Holthuis, 1952

– Carapace without supra-orbital tooth; dactylus of second pereiopod feebly curved, not hooked ……2

2. Second pereiopod with fixed finger of chela about as long as dactylus; first pereiopod with denticulate lamina along almost whole cutting edge of dactylus ……………………………………3

– Second pereiopods non-chelate, with fixed finger reduced to small stub or completely lacking; first pereiopod with denticulate lamina on distal 1/3 of dactylus …………………………………4

3. Anteriorly extended eyes shorter than rostrum; eyestalk short, about as long as wide; basal segment of antennular peduncle with 2–3 teeth on distolateral margin … H. noumeae Bruce, 1970b

– Anteriorly extended eyes far overreaching rostrum; eyestalk long, about twice as long as wide; basal segment of antennular peduncle with one distolateral tooth………………………………… ……………………………………………………… H. macrophthalmus Fransen & Rauch, 2013

4. Fixed finger of second pereiopod fully reduced, lacking; telson with 2 pairs of dorsal spines; basal segment of antennular peduncle with distolateral margin bidentate (cutting edges of first pereiopod with 3–5 teeth on distal 1/3) …………………………………… H. paraqabai sp. nov.

– Fixed finger of second pereiopod reduced to small but distinct stub; telson with 1 pair of dorsal spines; basal segment of antennular peduncle with multidentate distolateral margin (4 teeth, 1–2 in juveniles) …………………………………………………………………………………………5

5. Cutting edges of first pereiopod fingers with 1 tooth on distal 1/3; ventral rostral margin convex …………………………………………………………………… H. aqabai Bruce & Svoboda, 1983

– Cutting edges of first pereiopod fingers with 3–4 teeth on distal 1/3; ventral rostral margin straight ……………………………………………………………………………… H. pseudaqabai sp. nov.