Yes, the ocean contains worms—the so-called zombie worms (genus Osedax)— that seem to like the taste of whale bones. Scientists have discovered that these creatures may like to munch the bones, but without any mouth parts or a digestive tract, for that matter—how the animals eat has long been a mystery. In 2013, scientists finally made the discovery—the bone-drilling worms actually produce acid in large quantities. The acid is produced by what are called proton pumps, or protein-containing structures that exist at the front end of the worm’s body (to compare, human kidneys use similar proton pumps to process wastes). How they process the dissolved bone as food is still a question, but one suggestion is that symbiotic bacteria may be involved.

Continuous feeders, also known as filter feeders, are aquatic animals that constantly feed by having water filled with food particles (for example, small plankton or fish) entering through the mouth. In addition, they do not need a storage area, such as a stomach, for food. Discontinuous feeders must hunt for food on a regular basis; they need a storage area, such as a stomach, to house food until it is digested.