How do malacostracan antennae detect odors, sounds, vibrations, and touch?

Malacostracans utilize specialized sensory structures located on their antennae and antennules to detect environmental stimuli. These adaptations are a result of evolutionary shifts that freed these appendages for sensory functions.12

• Odors: Malacostracans detect chemical cues using olfactory hairs known as esthetascs. These structures allow them to locate food and recognize other members of their species, including their sexual states.1
• Touch: The external surfaces and appendages of malacostracans, particularly the antennae and food-gathering limbs, are covered in tactile setae (sensory hairs). These hairs detect physical contact and movement when deflected.13
• Vibrations and Sound: Malacostracans possess highly specialized receptors for sound and vibration. In amphipods, these include antennal calceoli, which consist of receiving elements attached to the antennal segment by a stalk. Advanced predatory amphipods use these to detect both mates and prey. Additionally, some malacostracans possess chordotonal organs on the hinges of their walking legs for sound reception.1

While these antennae-based systems are vital, malacostracans also utilize other organs, such as statocysts, to maintain balance and orientation relative to gravity.13