Final answer:
Arrow worms likely have a simplified but structured nervous system, similar to other invertebrates, which might include a nerve cord and rudimentary brain allowing them to sense and respond to their environment.
Step-by-step explanation:
Nervous System of Arrow Worms
Arrow worms, while not explicitly mentioned in the provided references, are a group of predatory marine invertebrates known for their distinctive arrow-like body shape. Similar to other invertebrates, invertebrate nervous systems vary significantly, ranging from simple nerve nets to more complex structures with central and peripheral components.
Most nematodes have a nervous system consisting of four longitudinal nerve cords and a well-developed ventral nerve cord, all fusing at the anterior end to form a pharyngeal nerve ring, serving as a rudimentary brain. Roundworms possess a primitive nervous system with a head ganglion that functions as the brain. This is indicative of a certain level of organizational complexity. In comparison, the nerve net found in cnidarians is a simpler form of a nervous system with scattered nerve cells forming nerve plexi or cords, which might be less complex than that of arrow worms.
The nervous system of invertebrates like echinoderms consists of a circumoral nerve ring and radial nerves, while insects possess a brain and ventral nerve cord with ganglia. Although we do not have specific information on arrow worms, they are likely to have a simplistic version of a nervous system that allows them to sense and respond to their environment, potentially with a centralized structure given their predatory lifestyle.