Ocypodidae

Rafinesque, 1815

Ghost and Fiddler Crabs

Genus Guides

Ocypode(Ghost Crabs)
Uca(Narrow-fronted Fiddler Crabs)

Ocypodidae is a of semiterrestrial crabs comprising approximately 180 described across 13 extant . The family includes two well-known groups: ghost crabs (genus Ocypode) and fiddler crabs (multiple genera including Leptuca and Minuca), plus the mangrove crabs of genus Ucides. Members are characterized by markedly unequal chelipeds in males, with the larger cheliped always exceeding length. The family underwent substantial taxonomic revision in 2016, when the genus Uca was divided into 13 separate genera.

Ocypodidae by (c) Jason Alexander, some rights reserved (CC BY), uploaded by Jason Alexander. Used under a CC-BY license.

Ocypodidae by (c) Caroline Voget, some rights reserved (CC BY), uploaded by Caroline Voget. Used under a CC-BY license.

Ucides cordatus by (c) Tim Hirsch, some rights reserved (CC BY), uploaded by Tim Hirsch. Used under a CC-BY license.

Pronunciation

How to pronounce Ocypodidae: /oʊˈsɪpəˌdaɪ/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Quadrate, transversely rectangular, or pentagonal that is markedly thick with moderately convex, smooth surface. Regions weakly defined or absent; lateral margins entire without dentation. Front markedly narrow, straight or very faintly bilobed, strongly deflexed. Orbits broad, occupying most of margin; eyestalks characteristically slender and long. Antennules fold obliquely to longitudinally with markedly enlarged, globose to ovate basal segment. with small basal segment and short . Third maxillipeds completely cover buccal cavern with gap between but never rhomboidal; exopod slender and sometimes very short. Chelipeds unequal, larger cheliped always longer than carapace, strongly sexually dimorphic. legs comparatively slender and long with characteristic pouch between bases of walking legs 2–3 or 3–4, serrated by setae, leading into buccal cavity and functioning as supplementary breathing system. with seven freely moving somites in both sexes.

Images

Habitat

Intertidal soft bottoms including mudflats, sandy beaches, and mangrove environments. Specific microhabitat partitioning occurs: some occupy supra-littoral sand dunes, others open beaches, and others marine inlets or estuarine khawrs.

Distribution

Tropical and temperate shorelines worldwide. Documented from the Persian Gulf, Arabian Gulf, Oman, Qatar, United Arab Emirates, Saudi Arabia, Panama, Hong Kong, Brazil, and New Zealand, among other locations.

Behavior

Acoustic and vibrational (substrate) communication documented in ghost crabs. Males of some employ search-intercept mating tactics without courtship or mate-guarding. Females may mate multiply with several males during limited receptivity periods. Burrow construction and maintenance is characteristic; some species construct hood structures at burrow entrances.

Similar Taxa

DotillidaePreviously classified within Ocypodidae but now treated as separate within superfamily Ocypodoidea; distinguished by different proportions and burrowing
MacrophthalmidaeFormerly included in Ocypodidae, now separate ; members lack the extreme cheliped dimorphism and characteristic orbital structure of Ocypodidae
UcididaeSegregated from Ocypodidae; contains mangrove crab Ucides which was formerly placed in Ocypodidae but now recognized as distinct based on morphological and molecular data