Symbiosis:

Another non-obligate symbiosis is known from encrusting bryozoans and hermit crabs that live in a close relationship. The bryozoan colony (Acanthodesia commensale) develops a cirumrotatory growth and offers the crab (Pseudopagurus granulimanus) a helicospiral-tubular extension of its living chamber that initially was situated within a gastropod shell.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". What species of crab has a helicospiral-tubular extension of its living chamber?
unanswerable