What is this?

[smoorman11]

 

[smoorman11]

The

The bottom photo is a black growth that latched onto my conch. The top photo is conch with the critter in question severed. Any idea what the black stuff is?

 

[nautical_nathaniel]

Can you provide more details about its characteristics and how it spreads?

I have some theories on what it might be but honestly haven't seen a black goo-like substance much in reef aquaria.