Who grow's the shell??

[daluminum]

I am curious as to who grows the shell that a hermit crab live's in.. My hermit crabs look like they are growing since the tip of the shell seems to be a softer color.. but I have heard that snail's grow the shell.. however I have a huge hermit crab.. about a 3" wide shell.. and I have never seen an astrea this big. so Im curious as to how the shell growth works in the ocean.. any clues??

 

[mr . salty]

The shells come from snails.Hermits can not grow thier own shells,or make the ones they are in bigger.That is why you need to provide them with a selection of shells for them to move into as they grow...And a snail grows it's shell not from the tip,but rather from the base,or hole...

 

[daluminum]

Thats what I thought.. thanks.