Hermit Crab lump on shell

[Danny19]

Hi
i was wondering if someone could let me know what this lump on my Hermit crab shell is
there seems to be something growing out of it.
i have the same thing on 2 of my crabs

 

[ISpeakForTheSeas]

Welcome to Reef2Reef!

The thing on your hermit there is a barnacle - I'm not terribly familiar with the species of barnacles that are parasitic on hermit crabs at the moment, but the ones I do know at present parasitize the back half of the bodies inside the shells, not the shells themselves. So, the barnacle on your hermit crab is most likely harmless.

Similarly, I've still got a lot to learn about crab parasitic barnacles, but the ones I recall at the moment attach to the crab's abdomen (ventral side) rather than their back/top (dorsal side), so if you're seeing little bumps like this one on your crab's backs, then those barnacles are likely harmless as well.