Cartilaginous Fishes of Zihuatanejo

CLASS ELASMOBRANCHII

• Animals (Kingdom Animalia)

• Chordates (Phylum Chordata)

• Vertebrates (Subphylum Vertebrata)

• Elasmobranchs (Class Elasmobranchii)

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Class Elasmobranchii comprises the sharks, rays, skates, and sawfishes, a major group of cartilaginous fishes within the class Chondrichthyes. With more than 1,200 living species, elasmobranchs inhabit marine environments worldwide, from shallow coastal waters and coral reefs to the open ocean and deep sea, with a few species occurring in freshwater. They are characterized by skeletons made of cartilage rather than bone, multiple gill slits, placoid scales (dermal denticles), and highly developed sensory systems that can detect vibrations, electrical fields, and chemical cues in the water. Sharks are typically streamlined predators, while rays and skates have flattened bodies adapted for life on or near the seafloor.