spaghetti worm or Amphitrite ornata very benificial
They can grow up to 12 inches long with feeding tentacles reaching 3 feet long.
Spaghetti worms build elaborate tubes for themselves, either in sediment or in crevices between rocks.
The worm secretes its own "cement" from glands on its belly, then lines its tube home with coarse sand and shell fragments. Little hooks along the sides of the worm grip the walls of the burrow and securely anchor the body inside.
Once snuggled down, the worm sends out feeding tentacles which constantly search the ocean floor for just about anything dead, dying or deposited there.
The moveable tentacles bear tiny hairlike structures along their surface and are able to curl up on themselves to form a groove.
When a tentacle finds something to eat, it forms such a groove and beats its tiny hairs, thus moving the food to the mouth. Sometimes a tentacle lassoes the food and drags it to the mouth, where the worm's lips wipe the tentacle clean.
IF you come across a spaghetti worm, you can watch these amazing tentacles in action. Gently touch one, and the worm will withdraw all its tentacles back into its body. Wait a moment, and they will gradually creep back out to resume feeding.
Hawaii hosts 11 species of these interesting reef cleaners; five of these are found nowhere else in the world.
