Heloecius

Heloecius
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Malacostraca
Order: Decapoda
Suborder: Pleocyemata
Infraorder: Brachyura
Section: Eubrachyura
Subsection: Thoracotremata
Superfamily: Ocypodoidea
Family: Heloeciidae
H. Milne-Edwards, 1852
Genus: Heloecius
Dana, 1851
Species:
H. cordiformis
Binomial name
Heloecius cordiformis
(H. Milne-Edwards, 1837)
Synonyms
  • Gelasimus cordiformis H. Milne-Edwards, 1837
  • Heloecius areolatus Heller, 1862
  • Heloecius inornatus Dana, 1851
  • Heloecius signatus Hess, 1865

Heloecius cordiformis is a species of semiterrestrial crab found in mangrove swamps and mudflats along the east coast of Australia. Adults are around 25 mm (1 in) wide, with males being larger and having larger and more conspicuously coloured claws. The males wave their claws to communicate with other crabs, giving them their common name of semaphore crab. They can breathe both in air and under water, and feed at low tide on detritus in the sediment. H. cordiformis is the only species in the genus Heloecius and the family Heloeciidae.