Three men have been arrested in Japan for attempting to smuggle hermit crabs out of the country.

The suspects, aged 24, 26 and 27, and widely identified in Japanese media as being Chinese nationals, were detained on Amami, a southerly island where the spiral-shelled crustaceans are a protected species.

Authorities were alerted to the men’s live cargo when hotel staff, who had been asked to look after their luggage, noticed the suitcases making a “rustling noise”, police told local media.

Officers subsequently discovered “thousands” of hermit crabs, weighing around 95kg. The third man was found to have a further 65kg in another set of three suitcases.

“Our investigation is ongoing to identify whether they had [the crabs] to sell them, or to keep them as pets, or to eat them,” a police spokesman told the news agency AFP following the arrests on Wednesday. “We are reviewing all possibilities.”

Police said the hermit crabs were “a national treasure”, being a part of Amami Island’s plant and animal diversity.

Hermit crabs – so named because they scavenge shells to live in – can regularly be seen on the beaches of the popular tourist destination.

The crabs can be worth up to ¥20,000 (£103), according to the Japan Times.