Mucus out of sand

[Storm Trooper Reefer]

i only saw this once, but no camera available. A worm like thing extended from the sand and released mucus like stuff in my reef tank. I’ve got some mucus floating around that I can net out, and some pellets that show up every few days. Any ideas what would do that? Live rock, 3 gobies, 2 clowns, 1 foxface, and a few zoas in my 50g with refugium. No algae, nitrate, nitrite, ammonia, phosphate all trace amounts (0-2 depending on when I test related to feeding and time of day). I think it some kind of worm, but have only seen it once when a tube came out of sand near rock

 

[James M]

Search spaghetti worm