grow on mollusc shells ( just look at queen scallops in many places ), the situation with netted dog-whelks seems to have a twist . I only very occasionally find a live netted dog-whelk overgrown with sponge , but I see many more small hermit crabs in the sponge-encased shells of netted dog-whelks . Are the little hermits very good at finding abandoned sponge-coated shells , or is it more likely that they actively put sponge onto a newly acquired shell in the way that spider crabs ‘ decorate ’ their armour ?
A particular recent encounter puzzled me even more . We were snorkelling at a sandy beach near Marazion in Cornwall and spotted a flatfish lying stationary on the sand . A couple of netted dog-whelks were crawling over its tail and there was another one just by its head that , judging by the trail left in the sand , could have headed there deliberately . I assumed that the fish was freshly dead and the scavengers were moving in to take advantage when , to my great surprise , the fish sped off in a cloud of sand ! Were the little molluscs ‘ jumping the gun ’ or could they even have been feeding on the fish ’ s mucus and dead skin cells , and thus benefitting their host ?
It ’ s yet another ‘ Critter ’ piece that ends with a query and the conclusion that the more you watch any animal , the more those questions emerge ! �
Netted dog-whelks crawling on the flatfish that gave me a surprise
The unusual sight of a netted dog-whelk encased in sponge
Netted dog-whelk moving through the sand with siphon held aloft
Distinctive netted dog-whelk egg capsules on seagrass
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