External

• Cephalothorax: This is the fused head and thorax region. It houses many vital organs and provides protection (Protection)
• Rostrum: The pointed extension of the carapace, it helps in defense and foraging by assisting in pushing and manipulating objects. (sensing)
• Eyes: Crayfish have compound eyes, which help them detect movement and changes in light. They are important for sensing predators and prey. (vision)
• Carapace: The hard outer shell covering the cephalothorax provides protection against predators and physical damage. (shielding/ protection)
• Abdomen: Contains the reproductive organs and parts of the digestive system. It's also important for swimming and balance. (Flexibility)
• Segments (somites): The body is segmented, providing structural support and flexibility for movement. (movement/flexibility)
• Antennules and Antennae: These are sensory organs used for detecting chemicals, currents, and movement in the water. They aid in navigation and locating food. (sensory)
• Mandibles: Used for biting and manipulating food. They play a role in breaking down and processing food before ingestion. (Chewing)
• Maxillae: Assist in manipulating and processing food before it enters the mouth. (Holding)
• Maxillipeds and Chelipeds: These are modified legs used for handling food, defense, and sometimes for mating rituals. (feeding/grasping)
• Walking legs: Used for movement on land or the bottom of bodies of water. (walking)
• Swimmerets: These appendages aid in swimming and are also involved in reproduction, specifically in carrying and fertilizing eggs. (swimming/reproduction)
• Uropods and Telson: These structures together form the tail fan and aid in rapid backward movement or escape. The telson is the pointed center of the tail fan. (stability/ defense)