Species: P. senegalus
They have long and slender in form, they are noted for a bunch of primitive features. Their scales are hard and shiny and are different from other fish by their rhomboid shape. The Dorsal fin is really made up of a bunch of smaller fins, kind of looking like saw edged teeth. This fin also gives them one of the common names (Sailfins) that we know them by. Unlike the more modern fish the Bichirs do not have a swim bladder but have developed an air breathing organ, which acts similar to a lung and allows them to gulp at the surface for air. This organ also allows them to live in very Oxygen poor water conditions. Another interesting feature of the fish is like Amphibians (Salamanders and Newts) The young must go through a larval stage in which they have external gills. These will be absorbed as the fish matures.
Biology and Behavior
Polypterus senegalus courtship starts with a series of leaps from the surface by usually only one of the pair at a time, followed by a slow descent through the water. After a while the male stays very close to the female and at times the female will remain motionless in the water and the male will come up to her from behind and nudge her with sidewise movements of his head. The enlarged and swollen anal fin of the male is folded in a cup-like fashion and is used to brush the female. No nest is constructed, but the eggs are laid a few at a time throughout the thick vegetation. The larvae, which move about with the male parent in a dense school, are provided with accessory gills and appear very salamander-like.
Habitat and Distribution
This species inhabits marginal swamps and freshwater lagoons and it appears to favor sheltered inshore habitats. it inhabits the muddy regions at the sides of rivers and swampy waters, where it lies quiet or glides about with snake-like movements