Fish

I asked Ai Gemini about fish and their sense of smell, yes, they have this. Here's Gemini's reply::

Fish "smell" through a process called chemoreception, which is essentially detecting dissolved chemical compounds in the water. Unlike humans who inhale airborne molecules, fish draw water through their nostrils (nares). This water passes over specialized sensory cells located in a folded structure called the olfactory rosette. These cells have receptors that bind to specific chemical molecules (like amino acids from food, pheromones from other fish, or alarm signals from predators). This binding triggers electrical signals that are then transmitted to the fish's brain, allowing them to interpret the "scent" and react accordingly for navigation, feeding, mating, and avoiding danger.