These impressive animals have a short, broad snout and stocky body that could be considered the “bulls of the sea.” They have long pectoral fins and saw teeth. The upper part of its body is gray with a green-brown hue, and its belly is white; If you notice dark spots on its fins, you will know that you see a young specimen because those spots disappear as they grow.
1. The skeleton of all the sharks is not of bone, is made of cartilage
2. They can adapt to freshwater even though they live in salty water.
The concentration of salt in their blood is barely 50%. They owe their ability to remain indistinctly in seas or rivers to a special gland located in the kidney. This system allows them to retain saltwater within their bodies for as long as necessary. As well as immediately expel the freshwater, avoiding the deadly effects that this liquid has for much other fish.