Occasional prey include arrow worms and tunicates.
The arrow worms (chaetognatha) undulate their finned bodies, not unlike fish.
Chaetognatha, commonly known as arrow worms, are a phylum of small predatory marine animals.
Eukrohniidae is a family of arrow worms.
Among lesser phyla of invertebrates are the Hemichordata, or acorn worms, and the Chaetognatha, or arrow worms.
Studies of arrow worms' nervous systems suggests they should be placed within the protostomes.
The Chaetognatha or arrow worms may also be deuterostomes, but more recent studies suggest protostome affinities.
The medusae live mainly off other medusae, comb jellyfish and arrow worms.
Walcott thought he saw three buccal spines in the fossils, and therefore categorized Amiskwia as a chaetognath worm (arrow worm).
The phylum Chaetognatha (arrow worms) may also belong here.
