Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and … See more

Bony fishes (Actinopterygii and Sarcopterygii) form a taxonomic group called Osteichthyes (or Euteleostomi, which includes also land vertebrates); they have skeletons made of bone mostly, and can be contrasted with cartilaginous fishes (see below), which … See more

Evolution of paired fins
There are two prevailing hypotheses that have been historically debated as models for the evolution of … See more

Fins can either be paired or unpaired. The pectoral and pelvic fins are paired, whereas the dorsal, anal and caudal fins are unpaired and situated along the midline of the body. … See more

Cartilaginous fishes form a class of fishes called Chondrichthyes. They have skeletons made of cartilage rather than bone. The class includes sharks, rays and chimaeras.
Shark fin skeletons are elongated and supported with soft … See more

Generating thrust
Foil shaped fins generate thrust when moved, the lift of the fin sets water or air in motion and pushes the fin in the opposite direction. Aquatic … See more

The use of fins for the propulsion of aquatic animals can be remarkably effective. It has been calculated that some fish can achieve a See more