what was this?

[mrabolli]

Srry guys no pic. Dont know if it woulda come out anyway. I watched a small tube/pistol type thing elongate and stretch really far fron between two "mouths" or circles of my green sea mat to eat from a peice of red macro nearby. Its tube body had a mouth at its end and would pick from the the red macro and retract partially then feed again. Any ideas. It was clear/opaqe and small.