Kladistiset

Kladistiset refers to a group of cartilaginous fish within the order Cladistida. This order is characterized by its primitive features, including a series of dorsal finlets instead of a single continuous dorsal fin. These finlets are a defining characteristic and contribute to the distinctive appearance of kladistiset species.

The most well-known member of the kladistiset group is the bichir (Polypterus). Bichirs are freshwater fish found in Africa, inhabiting a variety of environments such as swamps, marshes, and slow-moving rivers. They are predatory fish, feeding on smaller fish, invertebrates, and amphibians. Bichirs possess a pair of lung-like swim bladders, allowing them to breathe air from the surface when oxygen levels in the water are low. This adaptation is crucial for their survival in their often oxygen-depleted habitats.

Another genus within Cladistida is Erpetoichthys, represented by the reedfish or snakefish. Reedfish are also native to West and Central Africa and share many characteristics with bichirs, including the dorsal finlets and the ability to breathe air. They are typically more elongated and slender than bichirs, with a more serpentine body shape.

Kladistiset are considered to be among the most ancient lineages of ray-finned fishes, providing valuable insights into the evolutionary history of bony fishes. Their unique morphology and adaptations make them subjects of interest for ichthyologists and evolutionary biologists.