Appearance
The body is long and about as deep as it is wide. A serrated dorsal fin runs along most of the body until it meets the caudal fin. The pectoral fins attach just behind and below the gill openings, and are the primary means of locomotion, providing a slow, graceful appearance. P. senegalus is smaller than other bichirs, reaching about 35.5 cm (14 in).
The head is small and lizard-like, with a gaping mouth and small eyes on either side. Since its eyesight is poor, the bichir primarily hunts by smell. External nostrils protrude from the nose of the fish to enable this.
The fish has a pair of primitive lungs instead of a swim bladder, allowing it to periodically gulp air from the surface of the water. In the aquarium, bichirs can be observed dashing to the surface for this purpose. Provided the skin remains moist, the creature can remain out of the water for nearly indefinite periods of time.
This bichir's skin serves as a particularly effective armor.
Read more about this topic: Polypterus Senegalus
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