Hoplocypode occidentalis (Stimpson, 1860) 

On the sandy beach habitat of Pacific Panama, Ocypode occidentalis constituted 2.11% of the decapod individuals.
"Generally, the upper beach zone of South American sandy beaches is dominated by a low number of species. Cirolanid isopods (e.g. Excirolana braziliensis) are often encountered (DEXTER, 1974; BOCANEGRA et al., 1985), together with large numbers of air-breathing ghost crabs (Ocypode occidentalis)."
In intertidal zones of islands off the coast of Sinaloa, Mexico, Ocypode occidentalis was the 36th most abundant decapod of the 57 species. It constituted 0.16% of the decapod individuals, based on a non-rigorous sampling protocol. It was present at 5 of 14 sampling sites. The survey results can be found in the pdf linked to this species entitled Arzola-Gonzales_datatable.
Ocypode occidentalis "exhibit mimicry and are located in the soils of sandy beaches."
"HABITAT: Sandy surge-beaten beaches; sandy-silt areas adjacent to rivers where water flow is fairly rapid. ... They are scavengers and their rapid movements when disturbed contribute to their common name, ghost crab.
"If our luck holds, we should find some of the scavenging ghost crabs (Ocypode occidentalis) burrowed above the water line. These crabs emerge from their burrows at night to feed on Sargassum and other jetsam washed ashore (thus exploiting a niche very similar to the one occupied by the numerous talitrid amphipods of temperate shores)."
"Ocypode occidenralis is an omnivorous macroscavenger, emerging at sunset to feed along the drift line or swash zone of the sandy beaches upon which it lives. Other species of Ocypode, however, are microorganic detritus feeders, like fiddler crabs, or predators."
"The larger crabs may reach 150 mm in width. Smaller individuals seem to fall into 35-45 mm and 15-20 mm categories. Larger individuals tend to live higher up on the beach."
"I have found them to be common inhabitants of nearly every stretch of sandy beach in the Gulf, south of Puerto Lobos."
Based on it rarity in the Southern California Bight and Cortezian ecoregions, we assume Hoplocypode occidentalis is rare in the Magdalena Transition Ecoregion.
As of March 20, 2014, WoRMS uses Ocypode occidentalis and not Hoplocypode occidentalis.
Ocypode occidentalis is "most universally present" in exposed beaches (Zone 9) on the west coast of tropical America.
GBIF has a record Ocypode occidentalis in the Revillagigedos ecoregion. This record is part of the CNCR/Coleccion Nacional de Crustaceos data set.
"In southern Sinaloa, the ghost crab Ocypode occidentalis is omnipresent, although population density is never very high. It typically makes burrows in the sandy beach (habitat 1) [Unprotected sandy beach extending seawards, all along the estero], and is also occasionally found closer to the inlet area (habitat 10) [Muddy sand banks, unshade, bordering the inlet delta water]. It feeds on decaying fishes and crustaceans and is a devastating predator of eggs of the ridley turtle Lepidochelys olivacea(Eschscholtz) which oviposits in the area (BrisefloDuenas), 1980)."
Ocypode occidentalis is listed as occurring in Todos Santos Bay, west coast of Baja California, which is in the Southern California Bight Ecoregion.
Ocypode occidentalis is found in the supratidal zone.
Ocypode occidentalis is listed as a coastal lagoon/estuarine species.
"The species is known from a large number of localities on the American west coast from Mexico to Peru."
Intertidal sandy substrate and Intertidal pebbles and gravel
In the Gulf of California, "The typical animals found at the water's edge [of sandy beaches], as observed by this author are: Cerithium albonodosum, Bulla gouldiana, Heterodonax, numerous species of Donax, Uca crenulata and Ocypode occidentalis."
"A taxonomic revision of Ocypode Weber, 1795, has resulted in the recognition of a new genus, Hoplocypode containing a single species H. occidentalis (Stimpson, 1860) that is endemic to the East Pacific." Its range is from the Gulf of California to Columbia.
"Based on the characters given in Table 2, all reports of Ocypode occidentalis (= Hoplocypode occidentalis) from Peru are incorrect, because they were made, without exception, on the basis of juvenile O. gaudichaudii."
"Intertidal, sandy beaches and sand flats."
"Hendrickx (1995c: 142) reported O. occidentalis Stimpson, 1860 from Todos Santos Bay, west coast of Baja California. There are no other reports of this species from north of Magdalena Bay, Baja California."