The bootlace worm (Lineus longissimus), a marine invertebrate, is gaining attention for its unusual characteristics, including its remarkable length and toxic slime. While typically around 15 metres long, one specimen found in St Andrews was recorded at 55 metres, though some suggest it may have been stretched due to the species' elasticity. The worm is slender, with a width of just 5–10mm.
When threatened, the blackish-brown bootlace worm releases a poisonous mucus. Although its toxic slime was first noted in 1555 by Olaus Magnus, Swedish scientists fully described its toxins, known as alpha-nemertides, in 2018. These toxins are effective in paralysing and killing crabs and have also been found to kill cockroaches.
Researchers have observed that the alpha-nemertides have little impact on mammals, leading to the possibility that they could be used as the foundation for new insecticides. The invertebrate world is believed to hold many more useful chemicals and medicines yet to be discovered.