Hystrichis is a genus of nematode worm with a spinose anterior end, resembling the introvert of priapulids.A. Schmidt-Rhaesa, “Phylogenetic relationships of the Nematomorpha – a discussion of current hypotheses,” Zool. Anz., vol. 236, pp. 203–216, 1997. Species of Hystrichis live mainly in the digestive tract of aquatic birds.
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