» Posted by on Oct 23, 2017 in Blog, Cameron | Comments Off on Species Spotlight- Polypteriformes

Species Spotlight – Polypteriformes

by Cameron McMath


The longest river in the world, The Nile is home to an abundance of diverse and interesting species of wildlife. In an otherwise arid, dry climate many African organisms are dependent on The Nile for water and vital habitat, one such being the archaic Polypteriformes (polypterus and rope fish). Polypteriformes is an order of Actinopterygii found only in tropical African waters comprising of the bichirs and ropefish.

At first glance the polypterus may seem ancient and rudimentary, and indeed they do come from a time period more than sixty million years ago, however it poses a surprising number of interesting qualities. Adapted to survive in murky, hypoxic (low oxygen) environments, this peaceful predator possesses a number of advantageous traits including a keen sense of smell, as well as a modified swim bladder that allows them to gulp oxygen from the surface of the water. With thick ganoid scales and elongated bodies their snake-like appearance makes them a favourite for oddball tanks.


Juvenile Polypterus palmas


Tank Setup

Housing these reptilian-like creatures is rather simple, provided one has an adequate tank size and set up. While many polypterus are bought relatively small, it is important to keep in mind their potential for growth. Some of the smaller species such as the palmas and retropinnis grow to around a foot in length, whereas the behemoths like the endlicheri congicus can get as long as a whopping thirty-nine inches (three feet in length!) in the wild. Being that both the bichir and the ropefish are benthic (bottom dweller) organisms, they do require a tank with adequate width and length so as to maneuver and search for their food.

Lighting for these creatures is not too big a concern, as the polypterus eyesight tends to be poor. They hunt using two elongated sensory nostrils to detect prey or scraps for an impromptu meal, and due to their poor eyesight must literally scrounge around the bottom of the tank until they are right on top of their food.

Younger poly’s may be kept in smaller tank sizes, provided of course that their tankmates can’t fit in their mouth, however fully grown specimens will need to be housed in a minimum of 60 gallons with larger tank sizes are preferred for the polypterus to live comfortably. Predators tend to add a greater bioload to the tank, so it is important to make sure tank filtration is adequate or over filtered preferably.

As far as water chemistry goes, the polypterus is a rather hardy fish. Thriving in tropical water parameters (neutral ph, 78-80 Farenheit), they are also very tolerant of cooler temperatures and poor water quality as aforementioned their wild lifestyle often dictates adapting to available water conditions.


Adult Polypterus ornatipinnis



While polypteriformes are considered peaceful predators, their potential for growth and predatory status can make them tankbusters. When planning suitable tankmates it is important to make sure other fish cannot fit in the mouth of the bichirs. Other large fish make good companions provided they are not too aggressive and do not require any extreme water parameters. Some examples of good combinations with the bichir include certain arowanas, larger species of catfish, larger schooling fish such as lemonfin barbs, and certain peaceful cichlids like severums or geophagus. It is important however to be mindful of sizes and growth rates as they can vary between varieties of fish.



Many polypteriformes when first introduced into a tank are used to eating live or frozen meaty foods. While they can be kept on this diet, many fishkeepers will want to wean them off of live or frozen food onto a dry and more nutritious pelleted food, foods that can be soaked with such things as nourish or vitachem for added vitamins, amino acids and antioxidants for the fish. This can be accomplished, however it may take some patience. First you’re going to want to get your polypterus onto frozen bloodworm, fairly easy as they enjoy the juicy treat and can smell it the moment it is in the water. If you have difficulty with this do not worry, your polypterus may just be shy in a new tank. To make them more comfortable, add decorations or live plants to the tank, and try feeding at nighttime as they are nocturnal hunters in the wild and will need to get used to eating during the day. Once on frozen bloodworm, then switch to your desired food. Pelleted varieties come in all sizes depending on the size of your fish, ranging from omega one small pellets to the larger Hikari massivore or carnivore pellets.



Sexing the African snakefish is fairly easy, however at a young age the differences may not be so succinct. Females tend to be larger in size, while the smaller males posses a thicker, larger anal fin just beneath their tail. While captive breeding has been successfully accomplished, it is rather uncommon in tank-raised specimens. Should you notice spawning happening in the tank be sure to come in and show us, we’ll be just as excited as you to hatch and raise your little guys!

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