Sponge flies, also known as spongilla-flies (Neuroptera, Sisyridae), are specialist predators of freshwater sponges.
They use their mouthparts to parasitize Spongillidae freshwater sponges (e.g. of the genus Spongilla, hence the name "spongillaflies") and Phylactolaemata freshwater bryozoans by stinging into the host animals' body and sucking out cell contents.