Family HEXAPODIDAE Miers, 1886

Hexapus sexpes [from de Man 1888: pl. 13 fig. 3]

Museums

Regional Maps

• Hexapodidae Miers, E.J. 1886. Report on the Brachyura collected by H.M.S. Challenger during the Years 1873–76. Report on the Scientific Results of the Voyage of H.M.S. Challenger 1873–1876, Zoology 17(49): i-xlix 1-362 pls 1-29 [275].

Introduction

Hexapodids are a curious group of small crabs, remarkable for having only three pairs of walking legs. They have often been grouped as a subfamily of the Goneplacidae. However, the modern view is that they warrant separate family status (Manning & Holthuis 1981: 166). Only three species in three genera have been recorded from Australia. Hexapinus granuliferous (Campbell & Stephenson), is apparently indigenous to the eastern coast. Campbell & Stephenson (1970) reviewed Hexapus and provided a useful key, but Manning & Holthuis (1981) subsequently split the genus by creating Hexapinus; they also provided an extensive discussion of the species in both genera. The paper by Tesch (1918) is an important early work, but the best key to genera currently available is that of Manning & Holthuis (1981: 168).

Diagnosis

Carapace much broader than long; regions poorly defined; lateral margins convex anteriorly, more or less divergent posteriorly; front narrow. Antennules folded transversely; antennae small. Eyes typically small, reduced, with cornea scarcely wider than stalk, but may be hammer-shaped with cornea very large (Hexaplax). Eyes typically movable, but may be fixed (Lambdophallus). Third maxilliped varying in shape from broad, to slender and almost pediform; propodus slender or distally dilated; exopod with flagellum either present or absent. Chelipeds robust; three well-developed pairs of walking legs; last pair of legs lost, along with last segment of sternum. Male abdomen not filling space between last pair of walking legs; typically with several segments fused. Sternal grooves sometimes present in males of some genera. Female openings sternal.

General References

Campbell, B.M. & Stephenson, W. 1970. The sublittoral Brachyura (Crustacea: Decapoda) of Moreton Bay. Memoirs of the Queensland Museum 15(4): 235-302 figs 1-49 pl. 22 1 table

Manning, R.B. & Holthuis, L.B. 1981. West African Brachyuran Crabs (Crustacea: Decapoda). Smithsonian Contributions to Zoology No. 306: i-xii, 1-379 figs 1-88, 2 appendices

Tesch, J.J. 1918. The Decapoda Brachyura of the Siboga-Expedition. II, Goneplacidae and Pinnotheridae. Siboga Expéditie Monographie 39(c1): 149-295 pls 7-18

History of changes