RE: NANFA-- flatworms - what do they eat?

Hoover, Jan J ERDC-EL-MS (
Mon, 22 Apr 2002 17:42:55 -0500

Chuck wrote:
>>>Are the flatworms in my daphnia pond eating my daphnia? If they are, how
I get rid of them? If not, what are they eating? How did they probably get

Jan writes:
>>>Most planarians feed by extruding a long muscular tube out their mouth
and sucking up soft, semi-liquid tissues through it (like sucking a thick
creamy malt through a soda straw). Some planarians and some of the smaller
non-planarians feed by entangling tiny animals in their mucus stream, which
they then eat. One non-planarian has an adhesive organ at the top of its
head which it uses to grasp small prey (including small crustaceans).
Planarians I have kept have mostly eaten larger invertebrates such as dead
and dying segmented worms and amphipods. They will form a feeding frenzy if
presented with an injured earthworm.

So the flatworms in your pond might be eating some Daphnia - but it seems
more likely that they would be eating other larger, slower, moribund
invertebrates. Do not get rid of them. Enjoy them. Toss them some

Note - There is irony in the invertebrate world. Planarians which feed
protozoans are themselves food for a protozoan. The monstrous "swan
animalcule" Dileptus feeds on baby Dugesia dorotocephala as they emerge
fresh and wide-eyespotted from their protective cocoons.<<<
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