antennule

The antennule, also known as the first antenna, is a sensory appendage found at the front of a crustacean's head. In larval stages, antennules can be used for both swimming and feeding. In adult crustaceans, they primarily function as sensory organs, detecting physical and chemical stimuli. These stimuli can include tactile information, orientation with respect to gravity (via statocysts), and chemosensory detection of various substances. Olfactory receptors in crustaceans are often located on the antennules, allowing them to detect molecules in their environment.123