Freshwater hermit crabs are one of the rare species of living things found on earth. Before starting a discussion of freshwater crabs, it is important to mention that these crabs are found only in a single lake in the entire world, and are rare among rare exotic animals.
There are several species of marine hermit crabs, and all but one species are inhabitants of alkaline waters. Alkaline water crabs are native to different oceanic regions around the world and retain this origin even during captivity. That means the salinity and color of your captive waters must be like that of your native waters. However, although many marine species of these crabs have adapted to a captive environment in the company of humans, it is impossible to keep freshwater crabs as pets. Being a rare species, any type of human intrusion into its habitat is prohibited by international laws devised by wildlife conservation guardians.
The only freshwater reservoir where these rarest inhabitants of earth live is the freshwater roller coaster pool in Espirito Santo, Vanuatu, in the tropical Southwest Pacific. This coastal lake is located near the town of Matevulu and is located next to an abandoned airstrip. The species of hermit crabs that live in this coastal lake are the Clibanarius fonticola of the genus Clibanarius. Zoologists McLaughlin and Murray first reported this unique freshwater hermit crab habitat in 1990. Freshwater crabs are unique and prefer only the abandoned snail shells of the Clithon crown snail species. Clithon’s crown shells are found in their natural lake. The natural lake of Espirito Santo is fed with fresh water from nearby springs.
The reason freshwater hermit crabs have a unique habitat goes back to the unique confluence of conditions in their magical lake habitat. Always being fed by currents, this freshwater lake has a flowing water condition that is so essential for marine crabs to reproduce. Also, since the lake is located in a coastal region, there must be underlying elements of alkalinity in the lake water that make this habitat so favorable for crabs. This confluence of flowing water and underlying alkalinity makes the pool the only ideal place for the survival of the Clibanarius fonticola species. The distant and private location of the lake is also one of the main reasons these crabs have chosen the lake as their only freshwater home.
Some of the other members of the Clibanarius genus such as Clibanarius erythropus, Clibanarius signatus, Clibanarius tricolor, Clibanarius snelliusi, and Clibanarius englaucus can live in marine aquaria if their native conditions are adequately provided for in captivity. The Clibanarius genus, within the Diogenidae family, also has a very special identifying character. Unlike all other crabs, these crabs have an enlarged and decorated left claw, which is why they are also known as left-handed hermit crabs.
Although other marine hermit crabs do not need fresh water, surprisingly, land crabs only drink fresh water to survive. In this sense, it is perhaps not irrelevant to name these land crabs as freshwater hermit crabs. These land crabs drink fresh water for their nutritional needs, but prefer to bathe in a bowl of alkaline water.
