Download PDF as one large file - AToL Decapoda

Family Grapsidae
Key to genera and species
[Based on Rathbun, 1918]
Family Grapsidae 665
1. Antennules visible in dorsal view 2
Antennules hidden from dorsal view when folded 3
2. (1) Carapace broader than long Plagusia depressa
Carapace longer than broad ., Percnon gibbesi
3. (1) Third maxilliped without oblique hairy ridge on exposed surface of merus. 4
Third maxilliped with oblique hairy ridge on exposed surface of merus 10
4. (3) Ventral margin of orbit incomplete, paralleled ventrally by deep groove and strong
transverse crest; chelipeds very dissimilar 5
Ventral margin of orbit entire, usually sharply produced, not paralleled by deep
groove and supplementary crest; chelipeds similar 6
5. (4) Palm of major cheliped prolonged proximally far beyond its articulation with carpus.
, Platychirograpsus spectabilis
Palm of major cheliped normal Euchirograpsus
6. (4) Front much less than, half greatest breadth of carapace 7
Front more than half, or about half, greatest breadth of carapace. 8
7. (6) Fingers with broad, spooned tips.., Grapsus grapsus
Fingers acute, not spooned Geograpsus lividus
8. (6) Antennae excluded from orbit , Goniopsis cruentata
Antennae entering orbit '...-..• 9
9. (8) Carapace depressed, distinctly striated Pachygrapsus
Carapace convex, almost smooth Planes minutus
10. (3) Antennae excluded from orbit by tooth at lower inner angle of orbit meeting or
nearly meeting front Aratus pisonii
Antennae lodged in orbital hiatus 11
11. (10) Carapace quadrate or subquadrate. Sesarma
Anterior half of carapace with arcuate margin, posterior half rectangular
Cyclograpsus integer