Mechanoreceptors in non chordates?

Mechanoreceptors are sensory receptors that respond to mechanical stimuli such as pressure, touch, vibration, and sound. While chordates (animals with a notochord, including vertebrates) have well-studied mechanoreceptors, non-chordates also possess various types of mechanoreceptors.

1. Arthropods: Insects, crustaceans, and other arthropods have mechanoreceptors called campaniform sensilla. These sensilla are tiny, dome-shaped structures found on the exoskeleton that detect mechanical deformations and vibrations.

2. Mollusks: Mollusks, such as snails and squids, possess mechanoreceptors called statocysts. Statocysts are fluid-filled chambers containing sensory hairs and a small calcareous structure called a statolith. When the animal moves or changes its position, the statolith moves, stimulating the sensory hairs and providing information about gravity and orientation.

3. Cnidarians: Cnidarians, including jellyfish and sea anemones, have specialized mechanoreceptors called cnidocysts. Cnidocysts are stinging cells that contain a coiled thread-like structure called a nematocyst. When triggered by mechanical stimuli, the nematocyst rapidly extends, injecting venom into the prey or predator.

4. Echinoderms: Echinoderms, such as sea stars and sea urchins, possess mechanoreceptors called tube feet. Tube feet are small, flexible appendages that extend and contract using a hydraulic system. They are sensitive to touch and help the animal navigate and detect changes in the environment.

These are just a few examples of mechanoreceptors found in non-chordates. Different groups of non-chordates have evolved various types of mechanoreceptors to suit their specific needs and environments.