Geograpsus stormi de Man, 1895 

Arzola-Gonzalez, J.F., Flores-Campana, L.M., and Vazquez-Cervantes, A. 2010. Intertidal decapod crustaceans from the islands off the coast of Sinaloa, Mexico. Universidad y Ciencia 26: 179-193. The intertidal decapods from 14 islands of Sinaloa, Mexico (Cortezian Ecoregion) were sampled intermittently between 1995 and 2006. Though sampling was semi-quantitative, we used the total number of individuals captured at all 14 sites as an approximate estimate of intertidal abundance. In total, 57 species were reported with brachyuran crabs constituting 73.6% of the species.... The two most abundant species were the green porcelain crab (Petrolisthes armatus) and the brachyuran crab Eurypanopeus ovatus. The most wide-spread species was Pachygrapsus socius (= P. transversus of NEP authors), which was reported from 13 of the 14 islands. The Arzola-Gonzales et al._2010_Decapods_datatable.pdf file is located at species->pdfs.
Geograpsus lividus (Geograpsus stormi) was noted as common in the islands of the Gulf of California (Navachiste Bay) around mangroves and from clay soils.
In intertidal zones of islands off the coast of Sinaloa, Mexico, Geograpsus lividus (Geograpsus stormi) was the 14th most abundant decapod of the 57 species. It constituted 1.45% of the decapod individuals, based on a non-rigorous sampling protocol. It was present at 8 of 14 sampling sites. The survey results can be found in the pdf linked to this species entitled Arzola-Gonzales_datatable.
As Geograpsus lividus: "The width is about 25 to 35 mm. This species is found on both coasts of America, living among loose stones and rocks in the high tide and splash zones . On the west coast, it ranges from the central Gulf to Chile and the Galapagos Islands, and on the east coast from Florida to Brazil. I have collected it in the central and southern Gulf, living among the roots of mangrove trees at Topolobampo, and on the rocky shores of Cabo San Lucas, Bahia Kino, and Isla Partida. Crane (1947) remarked that this crab was principally a carnivore".
"Two species of fiddler crabs, Uca latimanus (Rathbun 1893) and U. crenulata crenulata (Lockington 1877), and the grapsoid crab Geograpsus lividus (H. Milne-Edwards 1837) [= Geograpsus stormi] were collected in the same habitat [under dead plants on sandy substrate, in the shade of mangrove trees above the water line]."
"Geograpsus lividus (H. Milne Edwards, 1837), from the Tropical Eastern Pacific region and western and eastern Atlantic Ocean, was once recorded from the Hawaiian Is. based on two specimens deposited in MCZ (Rathbun 1906: 839; see Edmondson 1959: 162). The record may have been the result of mislabeled specimens."
As Geograpsus lividus: "Under large loose stones on rock shores, or with substratum of coral and sand; rarely in similar localities near mangroves; lives well above low tide marks (Zone 2). ... Of five stomachs containing food, one held remains of a .minute sea urchin, two, insect remains (probably beetles), two amphipods, and two, a few bits of gravel."
As Geograpsus lividus: "Minimum duration of the complete zoeal phase (stages I-VIII combined) was 60 days. ... The first remarkable feature of G. lividus with regard to larval development is the number of zoeal stages. With eight stages, it has the longest recorded developmental pathway for any brachyuran. Six zoeal stages were the maximum number previously described for Grapsidae, for example P. marmoratus (see Cuesta and Rodriguez 2000)."
As Geograpsus lividus: Measurements.-Largest specimen, female: length 30 mm, width 38 mm, cheliped 50 mm, chela 25 mm, dactyl 15.7 mm. Habitat.-Rocky shore, above water line (spray zone). Depth.-Shore."
Geograpsus stormi [as G. lividus] live in the supratidal zone in the Galapagos. "They follow the receding tide, keeping always out of water but in the spray, which constantly moistens their gill chambers. G. grapsus has been observed feeding on sea lettuce, or Ulva, but is also known to be a scavenger."
GBIF has records of a synonym to Geograpsus stormi, Geograpsus lividus, in the Cortezian, Western Caribbean, Southern Gulf of Mexico, Northern Gulf of Mexico, Humboldtian, and Angolan ecoregions.
GBIF has records of Geograpsus stormi in the Gilbert/Ellis Islands, East China Sea, and South Kuroshio ecoregions.
Geograpsus stormi (as Geograpsus lividus) is listed as a rocky intertidal species.
Geograpsus stormi found in between rocks in an intertidal zone.
Galapagos: "Highest intertidal and throughout the breadth of the rocky shore tidal zone, following the tidal movements."
"Geograpsus stormi de Man, being a tropical Indo-Pacific species, has also been recorded northwards from Durban on the east coast [of South Africa]."
Intertidal rocky substrate
In a quantitative study of the decapods of the rocky intertidal of eight bays on Socorro Island, Revillagigedo, Geograpsus stormi (as G. lividus) was found in four bays. It constituted from 0.5% to 4.3%of the individuals where present. Of the 26 decapods, it was the 14th most abundant species, constituting 1.0% of the total decapods across all sites.
Geograpsus stormi: Size 20x29 - 30x38 mm (length x width). "In terrestrial areas along the shoreline, in pebbles or herbaceous areas. G. stormi is more terrestrial [than G. crinipes], sometimes observed in mountains and in forests."
"Habitat: supralittoral, near the splash zone of rocky areas and stone beaches; from middle to upper intertidal, beneath stones."
As Geograpsus lividus: "Measurements. Male (24041), length of carapace 24.8, width of same 30.2 mm. Habits. Lives among loose stones and rocks along shore above the water's edge. Probably nocturnal."
As Geograpsus lividus (H. Milne-Edwards) subsp. stormi: Breadth of carapace 35.25 mm, length of carapace 29 mm.