Sharks

Presentation of

SHARKS

Index

1. The gill slits

2. The nostrils

3. The difference between males and females

4. Diet-adapted jaw and teeth

5. The bulbs of lorenzini

6. 3 significants shark figures

7. Rays and Sharks

8. The leopard shark

the gills slits

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Gills slits are individual opening. Gills are characteristic of cartilaginous fish such as sharks. Most sharks and rays have 5 pairs of gill slits. Sharks have aquatic respiration. Water enters through the mouth as they move, passes over the gills, and then exits through the gill slits. Gill slits are openings located most often on each side of the head.

The nostrils

Sharks have nostrils called *nares* located under their snout. These nostrils are not for breathing but only for smelling. Sharks can detect tiny traces of blood or other scents in the water, even from far away. Each nare has two openings: one for water to flow in and one for it to flow out. This system allows sharks to constantly "taste" the water to find their prey. Their sense of smell is highly developed and plays a key role in their hunting.

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The differences between Males and females

Males sharks tend to be smaller than females. But the easiest way to tell them apart is to look for claspers, which are used for mating. This is like a pair of extra roll-up fins under their body.

Diet-adapted jaw / teeth

Sharks are ocean predators that eat many different types of food. What they eat depends on their species, size, and where they live. Sharks can eat fish, like mackerel or herring, as well as crabs, squids, and sometimes even sea birds. Bigger sharks, like the great white shark, hunt sea mammals such as seals or dolphins. Others, like the whale shark, only eat plankton, which they filter through their gills. Some sharks are scavengers and eat dead animals or waste. Sharks play an important role in the ocean by keeping marine populations balanced.

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The bulbs of lorenzini

The ampullae of Lorenzini are special organs found in sharks, rays, and other cartilaginous fish. They are located mostly around the nose and consist of small canals filled with gel, connected to tiny pores on the skin. These organs help the animals sense electric fields, even very weak ones, produced by the muscles and nerves of their prey or objects in their surroundings. This ability makes them excellent hunters, especially in dark or murky water, and also helps them navigate using the Earth's magnetic field.

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The gray shark has 336 teeth

The greenland shark has the longest lifespan (estimates at nearly 400 years)

In June 2021, the first baby leopards were born at Nausicaa. There were 16 babies, 8 males and 8 females.

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rays and sharks

Rays and sharks are closely related because they both belong to the same group called cartilaginous fish. This means their skeletons are made of cartilage, not bone. They both have rough skin covered with tiny tooth-like structures called dermal denticles, and they use special organs called ampullae of Lorenzini to sense electric fields in the water. Both are predators with sharp teeth, and they reproduce in similar ways, with eggs or live young.

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The leopard shark

Scientific name : Triakis semifasciataClass : ChondrichthyesYear of discovery : Girard, 1855Distribution : Western seaboard of north America, from Oregan to the Gulf of Calfornia (Mexico)Habitat : Leopard shark lives along the Western coast of the North American continent. It can be found swimming in kelp forests.Size: They measure on average between one metter and 1.3 mettersDiet: It feeds on small bony fishes and their eggs, cartilaginous fishes, crustaceans molluscs and worms Longevity: 30 years

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