By Gabriela Navas, Invertebrate Zoology Lab

Every time you find yourself walking along the beautiful Elkhorn Slough, do you admire all you see? I guess we would have a conversation about the birds, crabs, even the occasional fish you may have seen. What about the snails? Oh yes, what about them? They are actually intermediate hosts to unseen residents of the slough, the trematode Cercaria batillariae. Trematodes are also known as flukes, and even though they may have a bad rap in some circles, they merit respect. Their life cycles involve sometimes one or more hosts, specialized to supplying different needs of the trematode. Some trematodes are even known to take over a snail body and mind modifying its behavior in order to get to its next host! Check this out this video on the trematode species Leucochloridium making “SNAIL ZOMBIES”:

Snail Zombies? You may think primitive, but in fact trematodes have recently been shown to show the ability to form caste systems just like your everyday ant or bee. According to Hechinger et al this is the first time this has been shown in flatworms.

So, next time we take a stroll around the slough - let’s chat about the unseen, shall we?