A report on Fin, Fish and Pelvic fin

Pelvic fins or ventral fins are paired fins located on the ventral surface of fish.

Fins first evolved on fish as a means of locomotion.

During courtship, the female cichlid, Pelvicachromis taeniatus, displays a large and visually arresting purple pelvic fin.

In these cases, the male is equipped with a pair of modified pelvic fins known as claspers.

In biology, the term fish is most strictly used to describe any animal with a backbone, gills throughout life, and limbs (if any) in the shape of fins. Many types of aquatic animals with common names ending in "fish" are not fish in this sense; examples include shellfish, cuttlefish, starfish, crayfish and jellyfish. In earlier times, even biologists did not make a distinction – sixteenth century natural historians classified also seals, whales, amphibians, crocodiles, even hippopotamuses, as well as a host of aquatic invertebrates, as fish.