Pg:- 11 and 12
Antennae are equipped with a variety of sensory receptors, known as sensilla, which can detect mechanical, chemical, and thermal stimuli:
Chemoreception: Antennae have chemoreceptors that can detect chemical signals in the environment. This includes pheromones for mating, food odors, and other chemical cues essential for survival. Sensilla on the antennae bind to specific molecules, triggering neural signals to the brain.
Mechanoreception: Mechanoreceptors detect physical changes, such as touch, vibration, and air movement. These receptors can help insects detect predators, navigate through their environment, and communicate with other individuals through substrate vibrations.
Thermoreception: Some antennae have receptors that can sense temperature changes, aiding in the detection of suitable habitats and the regulation of body temperature.
Hygroreception: This refers to the ability to sense humidity. Certain insects can detect moisture levels in the environment, which is crucial for finding water sources and suitable conditions for laying eggs.
Specific Functions in Different Organisms
Insects: Insects like bees use their antennae to detect floral scents and locate food sources. Ants use their antennae for communication through pheromones, which helps them follow trails and identify colony members. Moths rely on their antennae to detect female pheromones over long distances.
Crustaceans: Crustaceans, such as crabs and lobsters, use their antennae to detect food and navigate their underwater environment. They have both short antennae (antennules) for chemoreception and long antennae for mechanoreception.
Antennae have evolved to suit the ecological niches and behaviors of different species. For instance, nocturnal insects like moths have highly sensitive antennae to detect pheromones in low-light conditions, while aquatic crustaceans have adaptations for sensing chemical signals in water.