The Convex Sentinel Crabs are very small crabs having an average carapace diameter of about 1 x 1,5 cm to 1,5 x 3 cm and exceedingly long eyestalks.
They live in the intertidal zone, where they can be found abundantly on muddy places near the outlets of small streams, and are therefore absent from islands without such freshwater streams, e.g. the Tuamotus. The crabs feed on smallest food particles, which they sift out from the sand.
These crabs dig their burrows in muddy sand, in which they flee at the slightest disturbance.
This species is distributed throughout the whole tropical Indopacific region, from the coasts of Africa up to East Polynesia, where it can be found in large numbers especially on the atolls of the Tuamotu Archipelago.
The animals mostly stay close to the beaches, where they feed on all applicable things they can get, including seeds washed up to the beach or fallen coconuts, but also washed up fish and dead seabirds.
Strawberry Hermit Land Crabs prefer the shells of sea snails of the genus Turbo.
 Alden D. Hinckley: Ecology of Terrestrial Arthropods on the Tokelau Atolls. Atoll Research Bulletin 124: 1-18. 1969
 J. C. Yaldwyn; Kasimierz Wodzicki: Systematics and ecology of the land crabs (Decapoda: Coenobitidae, Grapsidae and Gecarcinidae) of the Tokelau Islands, Central Pacific. Atoll Research Bulletin 235: 1-59. 1979
 S. A. Hathaway; K. McEachern; R. N. Fisher: Terrestrial Forest Management Plan for Palmyra Atoll: U.S. Geological Survey Open-File Report 2011-1007, 78 p. 2011
The Tahitian Prawn is a Indopacific species, its native area stretches from the rivers of the coastal regions of East Africa well into Central Polynesia.
The species shows some sexual dimorphism, with the males being larger than the females.
In Wallis and Futuna the species is cultivated commercially in taro fields.
On the Cook Islands the species is called koura-vai ti’aka, in Samoa all prawn species, including this one, are named ula vai.
 Gérard Marquet: Freshwater crustaceans of French Polynesia: taxonomy, distribution and biomass (Decapoda). Crustaceana 61(2): 125-140. 1991
 N. Mary; A. Dutartre; P. Keith; G. Marquet; P. Sasal: Biodiversité des Eaux Douces de Wallis et Futuna; Mission d’Octobre 2004. Rapport Final, Ministère de l’Outre-Mer 2006
This species was scientifically described in the year 2011.
Subfossil remains of land crabs have been found on the major Hawaiian Islands for many years, but their identity was not clear. Researchers identified the crab as a new species by comparing physical characteristics with specimens from various collections.
The Hawaiian Land Crab is now known to have occured on all of the larger islands in the Hawaiian chain. The species reached a carapace size of about 6 cm and was therefore probably the largest in its genus.
The Hawaiian land crab species vanished at about 1000 A.D., shortly after the arrival of the first Polynesian settlers resp. of the new animals that the Polynesians brought to the islands (chickens, dogs, pigs and rats).
 Gustav Paulay; John Starmer: Evolution, Insular Restriction, and Extinction of Oceanic Land Crabs, Exemplified by the Loss of an Endemic Geograpsus in the Hawaiian Islands. PLoS ONE, 2011; 6(5): e19916 DOI