Chaetognaths, also known as arrow worms, are small marine animals found throughout the world's oceans. They have a slender transparent body with fins and a tail that aid in locomotion. Arrow worms feed voraciously on plankton and small fish using spines around their mouth. Reproduction is hermaphroditic, with internal fertilization producing planktonic eggs. Locomotion involves bursts of undulating body movements propelled by tail fins and stabilized by side fins.