Vertebrate Classes Overview

Vertebrate Classes Overview

• Vertebrates are characterized by a backbone or spinal column, providing structural support and protection for the nervous system.

Agnatha (Jawless Fish)

• Distinguished by the absence of jaws and scales.
• Body covered with skin only.
• Examples include hagfish and lampreys.

Class Chondrichthyes (Cartilaginous Fish)

• Composed primarily of cartilage, not bone.
• Teeth are not fused to the jaw, allowing for flexibility.
• Possess well-developed fins.
• Notable examples are sharks, skates, and rays.

Class Osteichthyes (Bony Fish)

• Characterized by a bony skeleton, which is a contrast to cartilaginous fish.
• Varied species include salmon, carp, catfish, and walleye, highlighting aquatic diversity.

Class Amphibia (Amphibians)

• Includes an aquatic larval stage with functional gills.
• Eggs are typically laid in water, leading to a metamorphosis process.
• Development includes the formation of lungs and four limbs in adults.
• Common examples include frogs and toads.

Class Reptilia (Reptiles)

• Exhibit internal fertilization and possess an amniotic egg, which aids in reproduction on land.
• No larval stage is present in their life cycle; they breathe air through lungs.
• Generally classified as ectothermic (cold-blooded).
• Examples include turtles, crocodiles, snakes, and lizards.

Class Aves (Birds)

• Identified by features such as feathers, hollow bones, and air sacs for flight efficiency.
• Internal organs are reduced to enhance flight capability.
• Circulatory system includes a four-chambered heart.
• Examples include eagles, blue jays, and pelicans.

Class Mammalia (Mammals)

• Distinguished by strong skeletal structures, advanced nervous systems, and teeth that are often specialized.
• Notable characteristics include mammary glands for nursing offspring.
• Examples encompass a wide range of species: humans, cats, dogs, among others.