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Sensory
Chemoreception
The senses of smell (olfaction) and taste (gustation) in fish - often extraordinarily acute compared to terrestrial vertebrates.
System: Nervous Level: Beginner Discipline: Physiology
📖 Overview
Fish live in a chemical universe. Salmon can detect their natal streams water at 1 part per trillion. Sharks can smell blood at 1 ppm. Catfish taste their entire skin. Because water carries chemicals more efficiently than air carries scents, chemoreception is arguably the most refined fish sense.
⚙️ Mechanism
Olfactory rosettes in the nostrils hold thousands of chemoreceptor cells. Taste buds are scattered across lips, tongue, barbels, and skin - up to 175,000 on a single catfish. Molecules bind receptor proteins that trigger neural signals.
✨ Fun Fact
A catfish has more taste receptors on its skin than a human has on their tongue - by an order of magnitude.
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