During experiencing sea turtle conservation activities at Con Dao National Park (Con Dao special zone, Ho Chi Minh City), many tourists were also interested in observing the "tank crab" species that seems to only appear in Con Dao.
According to Con Dao National Park, this is the largest shallow crab in Vietnam and the Indochina region, with the scientific name Cardisoma carnifex", belonging to the dry crab family "Geocarcinidae", usually distributed quite widely in the Indo-Pacific and African waters.
It is not yet clear why in Vietnam, only in the mangrove forest area of Con Dao National Park, the regular presence of this crab species is recorded. Tank crabs have shells quite similar to dark brown hearts or chestnuts; adult crabs can have shells longer than 10cm, weighing 1.3kg, along with a wingspan of up to 30cm. The name "tank" also originates from its heavy, clumsy movement and large, like a mechanical wing.
Contrary to their aggressive appearance, this species has a shy personality, immediately hiding in bushes or withdrawing into caves when there is noise. Caves of tank crabs are dug on land, possibly up to nearly 2m deep, and they only leave their caves for about 18-20 hours a day to find food such as rotten leaves, fallen fruits...
Although living entirely on land, in the breeding season (November-December), female crabs will carry eggs and release them into the marine environment. Crab larvae develop in the sea until they become crablets, and return to the mainland to dig burrows to live.
According to Con Dao National Park, tank crabs are not on the list of rare animal species, but in the locality they are still being strictly protected by a small number, sensitive living environment... Tourists participating in the experience are only allowed to observe and explore the wildlife of this species and are strictly prohibited from arbitrary hunting. The locality is also making efforts to protect the environment, as well as propagate to people and tourists not to encroach on the living area of tank crabs, especially during the breeding season.
