A conservation group in Pingtung County is calling on the public to send them seashells to save homeless hermit crabs, which are facing a life-threatening situation because of people’s habit of collecting seashells that the crabs use for protection.
Houwan Preservation Association director Yang Mei-yun (楊美雲) recently initiated a “send shells to me” project on the Internet, calling on the public to send the association leftover shells from seafood restaurants.
Yang said the association would clean up the shells and distribute them on the seashore at Houwan (後灣) in Checheng Township (車城) to provide homes for hermit crabs.
Hermit crabs lack a carapace, so they scavenge empty shells and repeatedly change shells as they grow, to protect their vulnerable bodies, the association said.
However, the decline in the number of abandoned shells is threatening the existence of hermit crabs at Houwan, a recent study showed.
About 95 percent of the crabs in Houwan live in the discarded shells of giant African land snails, but these are unsuitable for the crabs because the shells are light and fragile.
The crabs also often face the risk of being stepped on, Yang said.
Many have been seen using unexpected items in place of shells, such as cans and even plastic bottle caps, she said.
Yang added that since hermit crabs are also popular pets for children, many people illegally trap them and sell them at night markets in central and northern Taiwan.
A study by Kaohsiung Medical University professor Chiu Yuh-wen (邱郁文) found that among the 400 butcher land hermit crabs, 1,500 viola hermit crabs and 60 indos land hermit crabs they recorded between May and July this year, only 1 percent of them were living in suitable shells.
July and August are the peak breeding period for hermit crabs on the Hengchun Peninsula, when many of them emerge from seaside bushes at night to lay their eggs on the foreshore, Chiu said.
Crabs living in plastic bottle caps are vulnerable to attack by ants, he said, adding that whelks, horned turban shells and egg cowry shells are considered suitable homes for the crabs.