An interesting creature called innkeeper worm dwells along coast of California. It is a fat marine worm that lives in a U-shaped burrow. It is also referred to as spoon worm. The worm reaches about 20cm long but their burrow can be several feet deep. It normally burrows in areas with sandy mud.
Many small species of fish like gobies take shelter in the mouth of the burrow. Tiny crabs, scale worms also take up residence in this convenient shelter. Clams living outside the burrow stick their siphons into it, taking advantage of current of water that passes through. Food, shelter and running water pumped by innkeeper worm attract the ‘guests’ to this burrow.
The innkeeper’s guests check in and check out as and when they wish. The innkeeper worms neither gain anything from their ‘guests’ nor harm them. The worms are eaten by fish like bat rays, leopard sharks and otters. The predators suck these worms and dig them out of their burrows.