dinosaur

The dinosaur eel is the common name for the Gray Bichir, senegalese polypterus, although it is a fish and not an eel. There are over a dozen species of this fish, but the Gray Bichir or Senegalus Bichir is the most common and popular with aquarists. This Bichir is covered in dark gray horizontal bands that become paler as the fish grows. Some Bichirs can reach over three feet in length, although most species, including the Bichir Senegalus, grow to about a foot.

natural habitat

In their natural habitat, they can be found in lakes, rivers, floodplains and swamps in Africa, especially the Congo River and the Nile. They are able to survive in waters with low oxygen content and can move in search of food or to find other wet areas in your house dry in times of drought.

Characteristics

The misnomer dinosaur eel (hereafter Bichir) comes from the prehistoric appearance of this elongated fish. Its snake-like body is covered in thick, bone-like scales made of an enamel-like substance called ganoin, resembling the earliest, now-extinct, ray-finned fish. It has a distinctive series of up to 18 small dorsal fins, each with a sharp spine, which are erected when shaken. Fleshy pectoral fins, which control the fish’s slow movement, are attached behind and below the gill openings. It can also travel on land using its strong pelvic fins. Bichirs can also breathe air through a lung-like modification in their swim bladder. Other features include a pair of nostrils, a long lower jaw, and external nostrils that protrude from the nose to allow the Bichir to hunt by smell as its eyesight is poor. Females tend to be larger than males, while adult males have thicker dorsal spines and wider anal fins.

Diet

Bichirs are predatory and essentially carnivorous and will attack and feed on small fish that are easy to swallow as well as slow moving fish. They will also eat insects, crustaceans and frogs. As they are nocturnal, they will feed mainly at night.

Breeding

After a series of energetic twisting motions, the male Bichir fertilizes the eggs by wrapping his anal and caudal fin around the female’s genital opening. He then spreads the eggs with flicks of her tail. However, it is difficult to get Bichirs to breed in captivity. Some aquarists have noted that even if a male and female are present, the male is often unresponsive and will not fertilize the eggs the female releases.

aquarium size

Due to the length of growth of Bichirs and their need to breathe air, it is important that they be housed in long tank aquariums that are not too deep, possibly even on a fish tank table. Aim for an aquarium that is at least three times the adult size of the Bichir you have or plan to purchase. Choose fish tank aquariums that are no more than eighteen inches deep and do not fill completely with water. This is important as Bichirs need to be able to breathe from the air and therefore must be able to quickly swim to the surface and return to the bottom where they dwell.

Being able to use oxygen from the air allows Bichirs to survive out of water for several hours. Given this and the fact that they have an instinct to leave one place in search of food in another, it is recommended to have a well-fitting lid on your aquarium!

aquarium decoration

A thin layer of soft sand or gravel is fine as a substrate. Bichirs also like hiding places, especially as they prefer to stay out of the light during the day. Therefore, it is much more pleasant for them to have sturdy plants, rocks, and tunnels that allow them to display more natural behaviors. Plants attached to wood work best, as Bichirs tend to displace rooted plants in the substrate due to their size and when searching for food.

water conditions

As they are tropical freshwater fish, Bichirs require a temperature of 75-85 F. They like a pH of 7 or slightly lower and prefer water that is a bit hard. Of course, frequent water changes are important to ensure good water quality in your tropical freshwater aquariums.

aquarium lighting

Bichirs are nocturnal, so they will normally be lethargic during the day and active at night. Instead of turning off the aquarium lights completely, provide the appearance of a natural dusk by installing a blue moonlight bulb so you too can experience some action from your Bichir.

Feeding

Being carnivores, Bichirs love to be fed bait, mussels, shrimp and bloodworms. They will also easily accept frozen foods. Some aquarists have tried to encourage them to eat dry food by providing it only until hunger overcomes them and have found that they can adapt well. However, I would like to mention that this is not your natural diet.

tank mates

Given the large size of Bichirs and their predatory nature, it is extremely important to pair them with suitable tank mates. Do not keep them with fish smaller than three inches which can provide a ready meal! Bichirs are best paired with larger fish as they won’t be as bothered by fish they can’t swallow. Siamese tiger fish, angel fish, large barbs, cichlids, and knife fish are all possible tank mates. It has been observed that suckermouth catfish have a tendency to suck on the skin of Bichirs, which irritates them, so having both types of bottom-dwelling fish is not recommended. Also avoid pairing them with overly aggressive species. In a very large tank it will be possible to keep several Bichirs together, as long as they are the same size. In general, they should tolerate each other, apart from fighting over food!

To keep or not to keep?

Bichirs are interesting fish specimens, but be aware of all the issues involved in keeping them, especially the size of the tank and the other freshwater tropical fish you have or plan to have. Bichirs also cost more to keep than other fish, although they are a very hardy breed. Keeping Bichirs in the right environment requires careful planning!

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