The Bootlance Worm (Lineus longissimus), also known as the Giant Ribbon Worm, is a strange creature which is found throughout the British Isles. It is extremely long, but less than an inch thick, and often spends most of its life in a knotted, tangled mass, disguising its true length. Its body is usually brown to black with a purplish or bluish head. They can be found across all manner of seabeds and can sometimes be found in the intertidal zone, occasionally trapped in rockpools and will often hide themselves away in cracks and crevices in rocks. Unlike other species of nemertea the bootlace worm does not have a proboscis which can be extended to attack prey. However, they are thought to be able to absorb nutrient directly through their skin (which may be why they have evolved to have such long bodies) and they are also thought to feed on animal matter. When handled or attacked this species can produce a mucus which is harmful to humans if ingested.
Longest Animal in the World?
A report from the 1800s states that a bootlace worm was found in Scotland which was, when untangled and fully extended, just over 55 metres (180 feet) long. This would make the bootlace worm the longest creature in the world. However, this report was never officially verified and it has to be noted that the bootlace worm has a somewhat stretchy body, meaning that the true length of the creature could have been well under the reported 55 metres. Certainly bootlace worms often reach lengths of 10 to 15 metres, and have been verified as reaching 30 metres.