Chaetognaths, commonly known as arrow worms, exhibit several distinctive anatomical features that set them apart from other marine organisms. One of the most prominent features is their head, which is equipped with one or two rows of sharp, needle-like spines. These spines are positioned in the anterior part of the body and are characteristic of chaetognaths. Moving posteriorly from the head, one encounters a paired lateral group of spines, which is often informally referred to as their ‘jaws.’ These grasping spines are a unique feature of chaetognaths and are used for capturing and immobilizing prey. Another notable characteristic of chaetognaths is their transparent body. This transparency allows them to blend into their aquatic environment and makes them difficult to spot. The body may bear one or two pairs of lateral fins, depending on the species. These fins are essential for locomotion and help chaetognaths maneuver through the water with agility. At the posterior end of the body, chaetognaths possess a caudal fin. This tail fin aids in propulsion and balance, enabling them to navigate effectively through their aquatic habitat. These distinctive features collectively contribute to the unique appearance and ecological adaptations of chaetognaths, making them intriguing members of the marine ecosystem.