by Timothy A. Pearce and Mandi Lyon
When a snail wants a bigger shell, it merely grows its shell bigger, persevering with the spiral. Nevertheless, when a hermit crab wants a bigger shell, it should discover a bigger shell to maneuver into. Consequently, hermit crabs depend upon snails to supply housing. Hermit crabs have smooth abdomens, that are susceptible to predators, so that they preserve their abdomens protected within snail shells.
There are amusing tales of a number of hermit crabs lining up so as of shell measurement, in a sort of pecking order. When a brand new shell turns into obtainable, the hermit crab highest on the pecking order holds onto the brand new shell and retains a good grip on its present shell as properly. It tries out the brand new shell, and whether it is an enchancment, the crab will rapidly transfer from one shell to the opposite, releasing the previous shell. The previous shell then turns into obtainable to the subsequent crab within the pecking order who examines it, and so forth down the road.
Apparently, hermit crabs don’t kill snails to get the shells, however as a substitute seem to maneuver into already empty shells.
This sequence of images was taken within the night of August 12, 2017, at Amherst Shore Provincial Park on the Northumberland Strait in Nova Scotia. The images present a hermit crab carrying the shell of a Canine Whelk (Nucella lapillus) encountering a Noticed Northern Moonsnail (Lunatia triseriata). The whole interplay took a couple of minute or so. The hermit crab approaches (Fig. 1) and climbs onto the moon snail (Fig. 2). The snail pulls its physique into its shell and blocks the shell opening with its attractive operculum, like a door that shuts the opening tightly (Fig. 3). The crab flips the shell over and the reddish coloured operculum is seen (Fig. 4). The crab probes into the aperture (Fig. 5). Then the crab walks away (Fig. 6), evidently satisfied that the shell will not be obtainable.
It’s exhausting to inform whether or not the hermit crab feels crowded in its present shell; it seems to be fantastic to us, however possibly hermit crabs are all the time looking out for higher lodging. The crab approached from the snail’s bottom, so maybe the crab didn’t discover that the snail is alive. The crab flipped the shell over, probed into the aperture the place it ran into the operculum.
How lucky to have the ability to witness such an interplay, and to have a digital camera to report the episode!
Mandi Lyon is the Program Supervisor for Faculties & Teams and Timothy A. Pearce is Curator of Mollusks at Carnegie Museum of Pure Historical past.
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Carnegie Museum of Pure Historical past Weblog Quotation Info
Weblog writer:
Lyon, Mandi; Pearce, Timothy A.
Publication date:
February 7, 2024