Parasites do very effectively for themselves, which is why they’re so frequent in the animal kingdom. Geoffrey Read, CC BY
If you’re an oyster lover, seeing a shaggy worm slither throughout your appetizer is revolting – regardless that such worms are innocent to individuals. An web search utilizing the key phrases “oyster” and “worm” will carry up a giant cache of photos, every one much less palatable than the subsequent.



As a biologist, I examine invasive species together with these mud blister worms. Despite their excessive gross-out issue, their parasitic existence are fascinating. While parasites do trigger hurt to their hosts, they’re additionally a essential piece of the planet’s ecosystem.

Shell-boring worms
Mud blister worms belong to a bigger group of segmented worms, collectively referred to as polychaetes. “Poly” means many and “chaete” means bristles in historic Greek. Mud blister worms are one in all many species that burrow into the shells of animals like oysters, abalone and scallops, the place they spend their whole grownup life.

Considering the shells of oysters and scallops are made up of calcium carbonate, which has restricted dietary worth, it might sound an odd location for a worm infestation. But quite than feeding on the shell itself, these worms create a tremendous community of tunnels throughout the shell’s matrix, utilizing it as a home quite than a meals supply.

This worm, Polydora cornutanhas, uses tentacles to snag passing algae and food particles, while its body remain safely ensconced in the shell of its host organism.
This worm, Polydora cornutanhas, makes use of tentacles to snag passing algae and meals particles, whereas its physique stay safely ensconced in the shell of its host organism.
The worms feed by protruding their tentacles out of tiny openings in the shell, the place they seize meals particles from the encircling seawater. Unlike different parasites, which feed immediately on their hosts, mud blister worms invade their hosts’ outer masking and will need to have meals delivered to them for survival.

How many worms can a single shell harbor? I as soon as counted greater than 120 worms rising from the shell of a closely infested Pacific oyster. The floor of the oyster seemed like some other, but as soon as it was immersed into a particular irritating answer, a beautiful variety of worms started to stand up, identical to a creature in a zombie movie.