What happens to a shellder if it's separated from it's host?

[Mr Popo in your mouth]

Say a Shellder Bit a Slowpoke and became part of a Slowbro. Now say The SpiralShellder got cut off from slowbro. The Slowbro would revert bake to Slowpoke, sure. But would the SpiralShellder revert back to a Shellder? Would it stay the way it is merely as an alternate form of Shellder, capable of evolving? Why are there no Grey Cloysters in the hands of trainers from when the Slowbro evolution reverted back?

Also, it should be possible to evolve the Shellder into a Cloyster while on the Slowbro tail so long as it's just an alternative form and not a separate Evolution chain.  

[Brandino Gambino]

One logical explanation would be that slowpokes tail acts as a megastone of sorts for shellder, megaevolving him into a defensive measure for slowbro (higher def sp def an hp stats) since i cant recall ever seeing or hearing of spiral shellder in the wild by itself. This supports the shellder reverting back to ita original form if it got seperated. Thats just my theory

Edit: slowking has spiral shellder on his head so maybe slowpoke in general is like a mega stone to shellder

2nd edit: depending on how the shellder is removed, either by prying it off or amputating the tail still in his mouth then maybe a spiral shellder in the wild would be possible  

[Mr Popo in your mouth]

Pikaberry

One logical explanation would be that slowpokes tail acts as a megastone of sorts for shellder, megaevolving him into a defensive measure for slowbro (higher def sp def an hp stats) since i cant recall ever seeing or hearing of spiral shellder in the wild by itself. This supports the shellder reverting back to ita original form if it got seperated. Thats just my theory

Edit: slowking has spiral shellder on his head so maybe slowpoke in general is like a mega stone to shellder

2nd edit: depending on how the shellder is removed, either by prying it off or amputating the tail still in his mouth then maybe a spiral shellder in the wild would be possible

This makes sense to me.

And I would assume that once the cut off tail ran out of nutrients the Shellder would spit it out, Effectively DeMega-Evolving.

New Item for Gen 7: Slowpoketailite.  

[Brandino Gambino]

Mr Popo in your mouth

Pikaberry

One logical explanation would be that slowpokes tail acts as a megastone of sorts for shellder, megaevolving him into a defensive measure for slowbro (higher def sp def an hp stats) since i cant recall ever seeing or hearing of spiral shellder in the wild by itself. This supports the shellder reverting back to ita original form if it got seperated. Thats just my theory

Edit: slowking has spiral shellder on his head so maybe slowpoke in general is like a mega stone to shellder

2nd edit: depending on how the shellder is removed, either by prying it off or amputating the tail still in his mouth then maybe a spiral shellder in the wild would be possible

This makes sense to me.

And I would assume that once the cut off tail ran out of nutrients the Shellder would spit it out, Effectively DeMega-Evolving.

New Item for Gen 7: Slowpoketailite.

Lol yea, i think team rocket was onto something when they took over azalea town back in gsc  

[Neko Akashi]

It dies and becomes a gastly