👉 Elasmobranchii, also known as sea brachians or sea bristlefishes, are a class of marine invertebrates that includes a wide range of species. They are characterized by their long, slender bodies and flattened tails, which are used for swimming and grasping prey. These animals have a distinctive pattern on their bodies, with a series of elongated spines known as the "spine" along the back of the body. These spines help to protect them