Say you’re looking to make the next generation of medical tape. You want something that will hold skin and other organs together while they heal. You want it to be more convenient than sutures and less brutal than staples. It has to stick easily, hold on tightly, and come off painlessly. There are worse places to search for inspiration than the guts of a fish.

Micro-needles, by Jeffrey Karp

Fish intestines are home to a group of parasites called spiny-headed worms, or acanthocephalans. Their most distinctive feature is a spine-covered snout that the worm stabs into the gut walls of its host. Once inside, it contracts two muscles and the long snout rapidly swells into a bulb, anchoring the worm in place. The fastened parasite can now drink deeply from the river of nutrients washing over it, absorbing them through its skin.

To the fish, the worm’s spiny head is a health hazard. To Jeffrey Karp, it was something to emulate. His team at the Brigham and Women’s Hospital in Boston have spent many years developing medical adhesives, constantly looking to nature for inspiration. In 2008, for example, they developed a sticky tape based on the feet of a gecko. And last year, they created artificial microneedles based on a porcupine’s quills, whose structure allows them to easy to stab into flesh but hard to pull back out.