Barred Bichir

P. delhezi is greyish in color, and specks of yellow or green coloration have also been observed. Compared to the dorsal side, the ventral surface seems to be lighter in color. It is a rather unique species from a notably old group of fishes, possessing several traits than set them apart from their close relatives. The dorsal fin is very distinct in its shape, made up of a series of individual spines. They have a mostly cartilaginous body, like a shark's, and the primitive shape of its jawbones are more akin to that of a salamander's than a fish. Another notable characteristic of P. delhezi is its modified swim bladder. In bony fish, the swim bladder is an internal, gas-filled chamber, an organ that likely evolved to help fish control their buoyancy and stay at their preferred water depth. In P. delhezi, the swim bladder also functions as a type of lung. The swim bladder is divided into 2 parts, of which the right hand section is considerably larger. This functions as an accessory breathing organ and means the fish can survive out of water for some time, provided it is kept moist. For this reason, Polypterus is the only known vertebrate to have lungs, but no trachea. Another aspect of the barred bichir, which illuminates its primitive lineage and surviving characteristics, are its scales. …

The barred bichir was first discovered in the Congo River, and is commonly found especially in the upper and middle portions of the Congo River. Although only found in nature in this small region of Central Africa, this species has been bred in captivity and has become a common fish for aquariums or aquarists.

A nocturnal species, P. delhezi relies significantly on their sense of smell, rather than their poor sense of sight when it comes to hunting and locating food. In the wild, the barred bichir will hide during the day, only emerging at night to hunt prey. Their diet is entirely carnivorous and includes more or less anything which can be sucked into their mouths, including small fish, insects, and worms. This preference for a meaty diet can be observed in both wild species as well as in those kept as aquatic pets, in which shrimp, prawn and mussels have been noted as the favored prey.

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