There are sharks near Texas

Knowledge pool
totally phenomenal - senses

fishes

Naturally, underwater animals do not sniff the air. It is therefore not possible to differentiate precisely between the sense of smell (in land animals actually the perception of volatile, gaseous substances) and taste (in land animals, the perception of dissolved substances). However, if one understands the sense of smell to be the remote perception of substances, one finds that some of the underwater inhabitants have a phenomenal smell.

The fish's sense of smell

The main olfactory organ of the fish consists of two olfactory pits, which are constantly flushed with water. But sensory cells that perceive flavors also exist on the fins and body of many fish.

Fish that have to travel long distances during their lifetime, such as salmon and eels, have particularly well-developed smelling abilities.

  • Eels have excellent smelling abilities

Eels

Eels are born in the sea, presumably in the Sargasso Sea near Bermuda in the Atlantic Ocean. The young eels migrate far away from here: into the freshwater rivers and lakes of Europe, where they grow up over several years. Finally - almost at the end of their life the greatest challenge awaits them: They have to swim the 6,000 km back to their home waters - only there they can successfully bring offspring into the world. Nobody knows exactly why this is so.

But how does a fish that has neither a map nor a GPS device find its way back into the vastness of the ocean? He can rely on his excellent olfactory ability: he can perceive fragrances that occur in water in extremely low concentrations. He can also smell stereoscopically. Its nostrils are two small tubes with which the eel can precisely locate the direction from which the smell and taste are coming.

Eels can smell the aroma of a dead fish at very great distances. They are the world champions in smelling among vertebrates and far superior to dogs. Anglers who want to kill them know this very well. They offer them bits of worm on the hook, as these bits have a stronger fragrance effect than intact worms. And they refrain from smoking as much as possible: An eel can perceive cigarette smoke and register it as a strange, annoying smell, which it shouldn't go near.

  • salmon

Salmon

Similar to the eel, the salmon also has to travel long distances in the course of its life. With one difference: it is born in the river and migrates into the sea. Finally, the salmon seeks "its" river again to spawn. In doing so, it is based on the earth's magnetic field and smell. Only this one river smells like its river to the salmon.

  • Sand tiger shark

Sharks smell blood

It is hard to imagine that there are living things that can smell a drop of liquid in a water-filled swimming pool. Sharks can. If possible, you shouldn't step into the same pool with an open knee and a shark. Because a shark would smell you quickly and probably eat you, although humans are not its preferred prey - it prefers fish and seals.


Sharks smell blood at a dilution of 1 in 10 billion. This enormous ability ensures their survival. They depend on finding food in the vastness of the ocean. That is why they specialize in odorous substances that promise them prey: amino acids, the building blocks of proteins. They are abundant in animal cells and in the blood and are perceived even in minimal concentration. On the other hand, they do not smell sugar.

  • Shark's nostril

Brain and olfactory organ

Research on sharks has shown that their olfactory center makes up two thirds of their brain mass. This shows the enormous importance of the sense of smell for these animals.

Your olfactory organs are on the side in front of the snout. While the shark swims, a constant stream of water washes through its oval, elongated nostrils. The water gets into the blind sacs behind it, the inner surface of which consists of numerous folds, the olfactory epithelium. Its surface is full of receptor cells that can perceive the smallest amounts of "foreign" substances in the water.

Not only does a shark use its sense of smell to track down potential prey, it also notices impending danger.

People take advantage of this: They try to scare off sharks by adding smelling substances into the water, the smell of which sharks are familiar with and which they have come to know as dangerous substances.

  • A porpoise - a marine mammal in the North and Baltic Seas

Whales are mammals. They have therefore developed completely different orientations than the fish. The perception of sound is probably more important to whales than the perception of smell. Because the olfactory nerve is completely regressed in all whales, the olfactory zones have not been examined in more detail and for a long time it has simply been claimed that whales cannot smell. This may also have been done to generally portray them as callous and so to justify the slaughter of the whales.


In the past, baleen whales had already found large olfactory fields and suspected that the whales might have a stunted sense of smell. Finally, in 1989, large fields were found in the harbor porpoise's nose, which are covered with olfactory membranes and whose olfactory cells function fully. Since the actual olfactory nerve is missing, these sensory cells are connected to the brain via the trigeminal nerve.

© Text: Evelyn Bargs-Stahl, Dr. Erika Luck-Haller