Most people have never heard of the bootlace worm.  Why would anyone be interested in the bootlace worm?  The bootlace worm has several very unusual and interesting features that you will hear about in this report.

The bootlace worm is a marine ribbon worm. This worm is very rare.  It ranges in size from one inch to ninety feet long, but most are from 2 cm to 3 ft long. They are generally red or brown in color.  

The most unusual feature of the bootlace worm is its proboscis.  A proboscis is a tube that is used to attack its prey.  When the proboscis is not in use it is stored inside the worm in a muscular sheath. When projected, the proboscis turns inside out like a sock, and can extend two or three times the length of the worm.

There are two types of bootlace worms. One is unarmed and the other is armed. The unarmed worms use their proboscis so that it works like a lasso to catch their prey and bring their prey to them. The armed worms use their proboscis differently. At the end of their proboscis there is a barbed spike used to stab their prey. Each stab releases toxins into the prey. Both of these attack strategies work efficiently because the worm can be further away from its prey.  In addition to feeding, the proboscis is used for defense and for burrowing into the ground.

The bootlace worm moves coral during the night. It spends most of the day hiding under leaves, rocks, and around coral. For an unknown reason bootlace worms gather in large numbers during the autumn.

The bootlace worm lives mainly in seas, next to coral reefs. Sometimes the bootlace worm lives in fresh water lakes.

Unlike most worms, the bootlace is carnivorous. The bootlace worm eats other invertebrates, crustaceans, and algae during the night.

This worm has a blood system, but it does not have a heart. The muscles in the worm move to make the blood circulate.  The bootlace worm is nonsegmented, unlike most worms, such as the earthworm, which are segmented.  

Bootlace worms can reproduce in two different ways.  First, they can reproduce by themselves, because they are a single sex.  Each worm can lay eggs and fertilize them itself.  Secondly, because they are extremely fragile, they can break apart easily.  Each fragment can rapidly regenerate into a whole new adult worm.

Now that you have heard about the bootlace worm, I hope you will agree that it is a most unusual creature.






Biodidac, A Bank of digital resources for Teaching Biology, University of Ottawa,

Biological Sciences, University of Paisley,

California Academy of Sciences, http://

Columbia Encyclopedia,, . 

Lancashire’s Biodiversity Partnership,,

University of California, Berkeley, Museum of Palentology,

University of Manchester, School of Biological Sciences and the Faculty of Medicine, Dentistry & Nursing's Teaching and Learning Website,


Thomas Carter
March, 2003

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