Everything about rope fish (Erpetoichthys calabaricus) is uncommon – its behavior in a tank, appearance and even its name. It has several ones: ropefish (or rope fish), reedfish, snakefish. But all these names denote one and the same species.
It is interesting to watch fish in a tank, easy to keep it but you should bare in mind that its tankmates must be average or large sized. Rope fish takes smaller fish species as a food, since it is a predator by its nature.
Habitat in the wild
The fish is from bichir family and order. The genus is spread in West Africa. The fish habitat stretches from Benin to Cameroon, at that the fish is most often encountered in Niger river delta. It prefers freshwater rivers and lakes, but you can also see it in brackish water basins.
Predator fishes as a rule are active at twilight and at night. This one feeds on small animals, but first of all on insects and worms. Rope fish looks for food by means of its organ of smell, since the fish has rather poor eyesight.
Erpetoichthys calabaricus has a long smooth body, that is up to 20 in (50 cm) long in the wild. However, in a tank the fish grows to become up to 37 cm (15 in).
There is no exact information about the lifespan, but according to info got from aquarists who have such a fish – it has been living more than 10 years already.
Rope fish or snakefish – the name itself says about the appearance. The thing is not only about its body shape, but also about its diamond shaped scales, which usually have light greenish or brownish tint on upper side of the body and beige-yellow tint over abdomen area.
Pectoral fins of the fish are orange or yellow and they make it look a bit funny, since they are close to its head and look like “ears”. So when you watch fish in a tank it seems that it is swimming and waving its ears fast.
In the wild these fish inhabit mainly in lentic or slowly flowing waters with low oxygen content. Due to this the fish has rather poorly developed sight and its main sensory organ is sense of touch and smell.
Because of low oxygen content in water reedfish has got used to get to water surface from time to time and breathe with atmospheric air.
They even have lungs for this, with their help the fish can stay out of water for some time (at the condition of high humidity outside).
Difficulties in keeping
Just like bichir this one is not demanding either, but it requires some specific tank conditions and tankmates to keep it successfully.
Therefore, it can’t be recommended to beginners, but for experienced aquarists care won’t be a challenging task.
Keeping in a tank
Is a typical night predator – its is deliberate, cagey and a bit slow. Though the fish is active mainly at night, it becomes more active at day and hides less if you regularly feed it during a day.
A tank of 52 US gallons (200 L) will do to keep a fish. It should be thickly planted or with lots of shelters (or it can have both). The fish needs shelters, this way it feels much safer, comfortable and behaves more actively.
The fish feels fine when tank water pH range is from 6,5 to 8 and comfortable water temperature for it is 22–28 °C (72–82 °F). Since this is a predator, it leaves a lot of organic waste, therefore a canister filter is required.
However, aeration is not necessary for a rope fish. Due to its anatomical organization features, it can swallow atmospheric air and take oxygen from it. This process is easy to be seen – from time to time a fish gets to the water surface and takes some air with its mouth and goes back to the tank bottom after that.
The fish needs free access to the tank surface, otherwise it’ll die from suffocation, since just gill breathing is not enough for it. In general, this fish is a classic representative of bottom dwellers.
Another important thing is that tank must be tightly covered. The thing is that reedfish can justle through any crack and often escapes from tanks. Even the thinnest crack will give the fish a chance to escape and it can travel quite a long a way by land.
If there are any chinks in a tank for tubes and wires, you’d better close them with a sponge. If you are performing water renew, cleaning the tank etc. and you need to leave the tank for some period of time, either ask someone to stay and watch the fish or close the tank tightly with a lid.
Rope fish in a split second can get away from the tank, but it can’t live without water for a long time. Any kind of lighting will do, but it’s desirable to have some dark shelters in a tank, without any bright lighting.
We also must mention, that fish doesn’t take good when you move it from one tank to another, due to this fact it may refuse to eat for several days and even weeks (without any serious harm for the fish itself, though).
Lot’s of shelters in a tank will help your new pet to get accustomed. An unmistakable sign of successful adaptation and that your new tank dweller has found its place in a tank, is that the fish has chosen one or two constant shelters, where it spends most of the time.
The easiest way to feed a rope fish is to give it with large bloodworms or worms. The fish is a predator, so it will hunt small fishes, especially at night.
If you feed the fish with pieces of calamari and prawns – this is good food for it. As for the dry food, for example, pellets for bottom dwellers – fish may eat them sometimes, but this is more likely an exception for it.
The most important thing is to make sure that your fish gets food in general and is not starving. This is especially important, if a fish has fast and omnivorous tankmates.
The thing is that when looking for food a rope fish uses its perfect smell and sense of touch.
The fish may swim close to a large bloodworm and won’t see it unless it touches the bloodworm with its barbels.
This doesn’t mean that the fish has heavy mind, it is really not easy for a rope fish to find food, when the smell comes from all sides.
It’s better to feed the fish 10-15 later after you finish feeding the rest of tank dwellers.
If you feed all of them together, your fish is likely to stay hungry. If you see that the fish has been starving, feed it before turning of the tank lighting or after this.
Secondly, tankmates must be larger than its mouth – otherwise the fish starts hunting and treat them as its prey.
At that, once the fish starts to hunt at night, nothing will make it stop doing this. Some time ago I didn’t take this fact into account and about a dozen of small tiger barbs disappeared from the tank.
The fish doesn’t have rather pronounced sexual dimorphism. There is an idea, that you can define the sex by counting rays on its dorsal fin – males have about 12-14 rays and females about – 9-12 rays.
Besides, female’s anal fin is smaller that that of a male.
There were described some cases of successful breeding in home aquariums, but these are very rare events and they don’t demonstrate any systematic character.
Therefore, the species you see on sale are caught in the wild or bread in fish hatcheries with the help of hormonal agents.