Like his namesake, Hulk the hermit crab cannot be contained.
His tendency to repeatedly outgrow or break through his shell means the National Marine Aquarium (NMA) is on the hunt for a new home.
Despite many efforts to source a suitable shell, Hulk – named after the green superhero with extraordinary strength – has failed to take to any of them.
He has recently been making do with a shell that does not quite meet his requirements.
Charlie Preston, senior biologist at the NMA in Plymouth, said: “Hulk is a White-Spotted Hermit Crab and like all crustaceans, in the early stages of life, this type of crab moults frequently as it grows at a faster rate.
“As they get older, the rate at which they moult reduces to around once every 10-12 months.
“When they moult, they increase in size by quite a bit, so usually they will try and source a new shell when or shortly after it happens – however, this may depend on availability of new shells that meet their required criteria.
“Hulk outgrows his shells at a faster rate than we can source him new ones but is also quite a vandal and has been known to chip or break them – hence his name.”
Now, the NMA – run by conservation charity the Ocean Conservation Trust – is teaming up with Plymouth College of Art in a bid to find the hefty hermit a forever home.
Product design and innovation, and 3D design crafts students will use techniques including resin modelling, glass-blowing processes and even 3D printing to create a comfortable, functional and aesthetically pleasing shell for Hulk.
Three finalists’ designs will be selected by the NMA’s knowledgeable husbandry team, brought to life with 3D, and the winning shell will become Hulk’s new home.
The White-Spotted Hermit Crab is usually found in the Indo-Pacific, which reaches from East Africa to Hawaii, and lives on coral or rock reefs, usually shallower than 20 metres in depth.
Hulk, otherwise known as the Giant-Spotted Hermit Crab, Dardanus Megistos, has been happily living at the NMA for six years.
Ms Preston, who oversees his daily care, explained: “I believe Hulk himself has moulted around eight to nine times since he has been with us.
“We have kept most of his moults, and the size difference between them is astonishing.
“His initial size was approximately one to two inches across, while the latest moult measures about eight to nine inches across.
“This type of crab gets quite large and can grow up to approximately 25cm in width – however, 10-12cm is the more frequently encountered size.”
White-Spotted Hermit Crabs usually inhabit old gastropod shells, with their favourite being discarded shells of the Triton Trumpet, but it has not been possible to source one for Hulk.
Hulk is cared for daily by the NMA’s dedicated animal husbandry team, who ensure that the system in which he resides is running correctly and the conditions are just right.
Ms Preston added: “We must also make sure the lid on his tank is secure and weighted down, as he’s a bit of an escape artist and is very strong.”