What are enemies of planarians?

Answer 1

Mostly high school students, I would think, as they seem to enjoy cutting their heads in half. This is enforced bisection, true, & while the planaria don't seem to mind this--planaria are among the world's most fascinating creatures &, if one cut far enough it is likely one would wind up with not one, but two planaria cut from the same carnal* cloth--still, the actuality strikes yr correspondent, here, as rather sadistic. Not to mention the coerced cutting. Their second most infernal enemy seems to be the scientist, some of whom decided to prove that even animals who can be cut into pieces & see via eyespots in lieu of eyes have memories. The lesson learned was not only do these animals--the planaria--remember but that, if one has cut one planaria into its twins, both twins remember as well as the animal of origin. That this experiment involved not only the cutting but the shocking by electricity of all these creatures also disturbs yr correspondent. However, that the planarian cannot only remember but can also learn does not surprise at least one of us, the one who is now writing this. If, instead, what you seek are actually the animals who predate upon the planaria, I will suggest that you research the flatworm. Planaria are members of the flatworm family, a family fascinating in itself. While the high school planaria is not a parasite of the human being [something which has, perhaps unfortunate for itself, kept it a classroom favorite possibly since the first relative of the first footed fish to wander on land decided to build a schoolhouse], many flatworms, indeed, are. When considering the giant, snake-sized tapeworms one occasionally reads of being removed from the unhappy corpus of some living human being who, up until its removal, was unable to figure out what ate at him--when thinking of this, one might also give a nod to the planarian. Unalike as they are, they are still relatives. You may know a few someones in a similar sort of relationship to yrself from yr own family. I certainly know I do. And even beyond that, yr question is a difficult one. Although it may seem that the planaria is a harmless little victim of science & hobbyists who fish them from ponds via tidbits of calves liver tied to string [so they can then cut their heads in half, hmmmm?], in its own environment the planaria seems much more likely to excrete its abdominal digestive juices all over an equally harmless infant shrimp before--before I force you to research what happens next yourself. Let me tell you: it is neither usual, nor is it pretty. I have also encountered the following dialog, hereby excerpted. True, it is not directly about the high school planarian but about its relative: ----------------------- Y: It's kind of muddy out here. I might even say swampy. Let's just say it's unpleasant. And you still haven't told me what we're looking for, Don. D: The creature we're looking for is carnivorous, cannibalistic, and slimy. It's one of the most ruthless predators there ever was. Y: I give up. D: Okay. We're looking for land planarians, otherwise known as flat worms. [edi note: the rest of this dialog is as vile as it is available: http://amos.Indiana.edu/library/scripts/flatworms.html] ----------------------- Ho-kay. I am still looking for something willing to eat ANY similar type of worm, including our perpetually sliced-into-siamese-twin. ::HOWEVER:: We do have Hint One. Note: It's cannibalistic. So a predator of at least the land planarian, larger than the high school planarian, is itself. The larger ones will eat not only their not so distant relatives, they might also not particularly gently nibble, planarian style, just about anything else. Hint Two: Nibbling "planarian style" has something of the arachnid about it. As for what will eat them: In desperation to curb the land planaria's depredation of the earthworm, an animal entirely harmless in any size or variety, the feeding of flatworms to snakes & salamanders has been tried. Tried, yes, but these endeavors seem to have been met w/ unfortunate, well, shall we say, distinct lacks of success. Instead it has been noted that the larger flatworm might, sans hesitation, chow down upon one or another random emergent salamander in its dire, now failed, attempt to launch itself into life. For what the words "chow down" mean to a flatworm I, once again, need refer you to yr own research. Or to the cinema, flatworm style, of Herschel Gordon Lewis, were there a cinema, flatworm style, of Herschel Gordon Lewis. But, again, the carnage created by this carnal* carnage creator incarnate, this tireless turbine of torment, the planarian is NOT the same planarian whose head you have just nonchalantly notched. Nope, these crazed carnivores are of the somewhat larger variety, or at least they are the larger members of some same or similar species. While all of these things are turbellarians, some are micro- & some are macroturbellarians, & the lengths distinguishing one subtype from another are just between one & ten millimeters. High school planaria of this type are actually called Tricladida [triclads]. Even the worst of them is not on size-par w/, say, a triceratops. &, finally for the flatworm's finality [finally], something does, yes, eat them. Fish. *carnal: No, it doesnt just mean that. Yes, it means something else, too & is appropriately used herein. Ah, look it up. It's only fair. I looked up flatworms.