As the Worm Turns

The patterns created in the sand by abyssal enteropneust worms have puzzled researchers for decades.  Now, with the use of time-lapse photography in waters more than four kilometers (2.6 miles) deep, researchers have solved that mystery. 

The enteropneust worms pictured above have transparent, gelatinous bodies that grow up to a meter in length and five centimeters thick - a giant in the deep-sea world.  It creates the spiral patterns ocean floor as it searches for food - swallowing sediment and defecating along the way.  The evenly spread loops of the spiral reflects the side-to-side movements of the creature's swollen head as it forages for particles of detritus in the sludge.

What had been puzzling researchers was how the spiral patterns appeared in isolation; they didn't know how worms traveled from the end of one pattern to the beginning of another. 

The time-lapse photography suggests that the worms swim, or more likely drift, from one spot to another.  The worm swept up food with its head and created a spiral fecal trail over the course of 39 hours.  At the end of this period, the worm emptied its gut completely and floated to another area to begin the process anew. 

Researchers had previously speculated that the worms might burrow from one point to another.  They believe that because detrital food is so limited at these great depths, drifting to a new feeding location allows the worm to forage over a much broader range than burrowing. 

The findings were published in today's issue of Nature.