GEOGRAPHICAL DISTRIBUTION:
Polypterus is found in the rivers of tropical Africa, the Nile, Nigeria and Congo, Palezoic and recent, but none known species.
COMMENTS:
i) Polypterus is also known as Bichir.
ii) It is one of the most primitive living bony fish.
iii) Body is elongated about 1 m long and covered with rhombic ganoid scales.
iv) Spirade is present and there are four gill-arches.
v) Air-bladder is bilobed and cellular serving for respiration.
vi) Caudal fin is symmetrical externally, pelvic and anal fins are small.
vii) It feeds on small fishes, amphibians and crustaceans.
viii) It is most active at night when it searches for food.
ix) It does not readily live out of water, rarely longer than 3-4 hours and then only when covered with damp grass.
ECONOMIC IMPORTANCE:
– Big species are caught for food,
– Small species are reared as aquarium fish.
