That Fish Blog – Aquarium Advice and Information
Hello, Frank Indiviglio here. I have always favored fishes that seem to straddle the line between the fish and reptile/amphibian kingdoms. Included among these are both marine and freshwater forms, including the toadfish, frogfish, lizardfish, lungfish, mudskipper (note the common names!) and others. The freshwater fish family Polypteridae, containing the bichirs and the reed or rope fish, has long fascinated me and seems very popular with visitors to the exhibits I have worked on at the Maritime Aquarium (Norwalk, CT) and the Bronx Zoo.
Few if any bichirs have been well-studied, and even the most commonly available species are rarely bred in captivity; much can be learned by the patient aquarist.
Description
The dorsal fin rays of these elongated, snake-like fishes are separated from one another, rising and falling in a series of humps and lending them the appearance of scaled-down dragons. This effect is most evident in the aptly named Senegal dragonfish (please see below). The pectoral fins are rimmed with fleshy lobes, and are paddle-like in shape and function.
Swimming takes the form of short bursts, but mainly these fish scull along the bottom. The largest, including the commonly sold reedfish, can reach 3 ½ feet in length, but most are considerably smaller. Although dissimilar externally, bichirs are believed related to sturgeons, paddlefishes and gars.
Range and Habitat
Bichirs are limited in range to tropical Africa and the Nile River system, and are usually associated with shallow, plant-choked waters such as marshes, swamps and the shores of slow-moving rivers.
Future Amphibians?
The amphibian-like qualities of the bichirs are not limited to appearance alone. The swim bladder has evolved into an accessory breathing organ, allowing them to breathe atmospheric oxygen and to survive out of water for some time…few species are rumored to voluntarily leave the water for short periods. The young of some species even sport external gills, much like salamander larvae!
Reed or Rope Fish, Erpetoichelys calabaricus
This brown West African native has a sinuous, snake-like body and a wide mouth. The reedfish hides under the mud by day, emerging at night to feed upon insects, fishes, worms and frogs. It can reach a length of 3 ½ feet, but rarely attains that in captivity.
Senegal Dragonfish or Cuvier’s Bichir, Polypterus senegalus
Rounded, widely-separated dorsal fin rays lend the Senegal dragonfish an uncanny resemblance to its mythical namesake…it really does look like a miniature dragon!
Senegal dragonfishes are distributed throughout the Congo Basin and reach 12 inches in length. They make hardy, interesting aquarium pets and often learn to anticipate feeding times. The effect of a large specimen in a well-planted aquarium is quite spectacular – they definitely deserve more attention from aquarists.
Ornate Bichir, Polypterus ornatipinnis
Swamps and marshes in West Africa are the home of this commonly imported bichir. Patterned with a lacework of black markings, the ornate bichir is one of the more attractive members of its family.
Unfortunately, due to its unique appearance, the ornate bichir is often purchased on a whim. Few realize that the youngsters sold in pet stores eventually grow to 18 inches in length, and are often aggressive towards tank mates. However, properly accommodated ornate bichirs make fascinating pets, and, as they are rarely bred in captivity, are ideal species to study.
Further Reading
You can read more about bichirs, and see a list of all recognized species, at http://www.fishbase.com/NomenClature/ScientificNameSearchList.php?crit1_fieldname=SYNONYMS.SynGenus&crit1_fieldtype=CHAR&crit1_operator=EQUAL&crit1_value=polypterus&crit2_fieldname=SYNONYMS.SynSpecies&crit2_fieldtype=CHAR&crit2_operator=contains&crit2_value=&group=summary&backstep=-2.
I’ll address captive care in more detail in the future. Until then, please write in with your questions and comments. Thanks, until next time, Frank Indiviglio.
Polypterus senegalus image referenced from Wikipedia and originally posted by Zhyla
Rope fish image referenced from Wikipedia and originally posted by Michael Zalewski
i was wondering if it was normal for my dragonfish to barley be active he stays at the bottom of the tank for hours in the same spot and wont swim around. also i was wondering what you recomended for food???
That is pretty normal behavior for them, they lay around most of the time, but may become a little more active during and after feedings. Dietary offerings should be varied from live and frozen worms like blackworms, bloodworms or mysis to shrimp pellets, flakes and other foods that will sink to the bottom. Do bbe careful not to overfeen as extra food will end up rotting in the substrate. Frozen cubes are an easy way to portion and more nutritious and filling that processed foods.
my dragon fish looks like he has a bump close to the back of the head area is that normal the fish acts normal and still eats..Just wondering thanks
It’s difficult to say without seeing the anomaly you’re referring to. Normally the top of their head runs relatively smooth to where it meets the dorsal fin. If you’re able to snap a clear digital photo, you can send it to marinebio@thatpetplace.com and they may be able to give you better input. As long as the fish is eating and behaving normally, it should be nothing too serious, perhaps a benign tumpr or cyst.
hey..may i knw?? DragonFish can mix up with others fish such as Guppy ??? or Tetra fish
any other non-aggressive fish suitable for brackish environment will do, guppies, gobies, ect.
How big they can grow in captivity?
Captive max size is dependent on a variety of factors including tank size, feeding habits, ect. Most will be limited by their captive environment so it’s difficult to say what max size could be.
My dragonfish Eats everything! I like him too much to get rid of him but i only have other fish a mono and two Candycane extras.. How do I get him to stop? I Bought 50 shrimp and he ate them all in one day..
The only real option is to house him with fish that are too large to eat. Predators by nature, these fish will of course eat anything they see as potential dinner items. Shrimp are a prime offering.