The Snakehead Forum

The Rainbow Snakehead
By J.Vierke
Translated into English by U. Alsfasser



Introduction

One of the most colourful Snakehead’s is Channa bleheri. I have called it, for that reason Rainbow Channa. The Scientific name is credited to Heiko Bleher, who caught the fish together with Deepak Nopany and brought live specimen to me for scientific evaluation.

I first successfully bred the Rainbow Channa in December of 1988. The pictures of the breeding activities of those snakeheads shown here show the activities of the F1 brood in the summer of 1990. The observations of the breeding behaviour of this species where first published in the magazine ”Das Aquarium” issue 266 in august 1991. They include not only a report of their breeding behaviour but also insight into the reproduction behaviour of snakehead fish as they where previously not known, as well as the first pictures of the actual spawning of a snakehead species. Pictures of pretend spawning, spawning embraces preceding the actual spawning act where available.
Highly interesting observations were made by Walter Armbrust (African Channa) and G. Etterich (Channa orientalis and Channa gachua)




Housing

The main problem with Snakeheads is the appropriate housing in the right Aquarium. Anyone who has the choice of large and well planted aquarium doesn’t have to worry about those problems. The bigger the aquarium, the better it is structured by wood (roots) and stones, the denser the vegetation, the better it is to keep the fish correctly In my case I was forced to house the fish in a 100 litre tank. There the fish bred successfully. I must say that I regard this as the absolute minimum even for rainbow snakeheads. Its was quite long with 1.1m (44”) but quite narrow and shallow with only 30 cm (12”). The larger species need bigger tanks if the aim is to breed them successfully.

Channa bleheri are best kept in pairs. Unfortunately it is almost impossible to name external indicators towards the fish’s sex. The females are mostly smaller and have a larger belly when ready to spawn. Fortunately the fish themselves can tell, better then any of us, if their tank mate is a suitable mate or a competitor. Competitive battles will develop amongst same gender snakeheads after a few weeks at the latest. The end result of those battles are usually dried up Channa corpses on the floor. The weaker Channa will try to leave the unattractive water and leap from the tank with fatal consequences. No matter how hard the Channa keeper try’s to cover and gap in the tank cover eventually one of those accidents will very unfortunately happen.
(in my experiences Channa bleheri are the worst escape artist of all Channa. U. Alsfasser)

Even amongst males and females those fights are not unknown. Of course it is the smaller female that gets the brunt of it and sometimes, she does not dare to leave her hiding place. In that case the female need to be target fed to avoid starvation. Again it is clear as with most case: the smaller the aquarium the bigger the problems will be.

I have kept my rainbow cannas between 22 and 30 degrees. The water came from the tap at 14 degree dgh and was often mixed with rainwater. As with most cannas rainbow snakehead do not seem to have any species specific needs regarding their water chemistry

For breeding purposes it is advisable to use softer water to avoid the loss of the eggs due to fungus which can easily happen.


Explanatory note. New findings have shown that Channa bleheri, aswell as other snakeheads from Assam such as Channa aurantimaculata and Channa stewartii profit from a winter break at lower temperatures. Climate data from Assam also suggest this. My experiences with wild caught animals and F! show it can be done without a winter break


Feeding

Anyone who has a garden available where garden worms can be found in abundance does not need to worry about the diet of their snakeheads. A fully grown Channa bleheri will be happy with one or two medium sized worms a day. Once in a while mealworms are a welcome treat. I also tried to feed guppies to my cannas, which they like to eat but once the feeders realise the danger they understand to stay out of the snakeheads way. Eventually the cannas will give up. It can come to some amazing Combination. (Etterich successfully kept Channa orientalis with Malpulutta kretzeri for a long time). It has to be said that with most other Channa species it would be impossible


Courtship behaviour and spawning

It appears the successful reproduction of these fish is only possible when keeping just a pair. I could not, and I did look for it, find any gender specific differences in my fish. In colouration and finage both, male and female, are identical. In animals of the same age the female is always smaller. It seems to be the same in juveniles and males appear to grow much faster. Adult females can be distinguished by their belly’s once they are ready to spawn. Then females are much fuller in the belly region then the males.

A well suited pair of Channa bleheri is totally peaceful. Only periodically there are short arguments if one get a piece of food right in front of the others face. In larger tanks male and female prefer to remain at opposite end but always venture across. But both partners seek physical contact. Especially the female approaches the male regularly as if to see he is still there. Sometimes there appear to be romantic encounter. Those physical loose embraces have the purpose to dampen the aggression, especially in the male

Occasionally it can happen that this harmony suddenly collapses. Then a indiscriminate hunting and biting follow where the female is usually at an disadvantage

The especially peaceful periods can last for month . They appear to be connected to the reproduction cycle. If the spawning has been unsuccessful, ( for example to fungus), the cannas can spawn again every two weeks

Rainbow snakeheads entering the reproduction cycle need to be fed very well. The female will now develop a huge appetite and will soon have a swollen belly. During this time the male visit’s a sheltered place where it will predominantly remain. This will be the future spawning site- this is how it was with my fish

In the last days before the spawning bodily contact will increase. The female will enter the male territory especially often in the last two days. The fish will circle each other and the first embraces will occur. Those pretend spawning are a reminder of the breeding behaviour of labyrinth fish. Both partners will encircle each other tighter and tighter until they form a knot below the water surface.

In some specific points there are differences. The mentioned pretend spawning can be seen two or mare day before the actual spawning act. It is typical for Channa bleheri that the intensity of the embrace increases, from a loose loop to a tight knot, aswell as the length of those pretend spawning.

Eventually there will be a single mating with one spawn release. It takes about 30 seconds.

The now tightly embraced pair releases all its eggs in one single burst. The glasslike transparent eggs are lighter then water and immediately rise to the water surface.



The eggs are fairly small. I measured them under the microscope. The eggs have a diameter of between 0.9 and 1.1mm(for comparison Channa orientalis are 1.1 to 1.1 mm). In the top of the egg is a clear oil base (diameter 0.6 to 0.7mm) and below is the actual egg (diameter 0.4 to 0.5mm)




Care of the young


Already after the last few pretend spawning male and female search the water surface for eggs. At least this is how it appears when they seem to feel for eggs using their nasal extensions in the vicinity of the spawning site

After the spawning both fish will gather the eggs in their mouth’s and immediately release them again through the gills until they are all gathered in a type of raft.
Now the father stays below or beside the eggs without taking his eyes of the raft.
If one as keeper takes a few eggs from the raft, for examination below the microscope, it appears not to bother him much. He shows no reaction


From time to time both parent will collect eggs in their mouth and release then again through the gills as described before. I presume the eggs are kept free from dirt and parasite this way and the antibacterial substances in the mouth could play a important role

Similar things are known with labyrinth fish, but in those cases it is single and not numerous eggs

The following photo shows this behaviour


The care for the fry was also taken up by both parents. The to begin with colourless young are canary yellow in the upper body at a size of 1cm. On the head they have a dark stripe beginning at the tip of the lower jaw , through the eye and ending at the lower rim of the gill cover. The lower body is in contrast to the yellow upper body smoky grey to black. The small Channa circle their parents like a swarm of mosquitoes.


It is noticeable that the young establish a lot of bodily contact with their parents. Often the young rest on the head of their motionless resting parents. It appears they eat a secretion of their skin. The young fry plug their parents body and fish separated at this stage do develop a lot slower as the once remaining with the pair. This is convergent of the behaviour of so cichlids, in labyrinth fish this behaviour is unknown.

In the following weeks the baby colouration dulls and is replaced by a inconspicuous youth colouration. Now the young Channa do not care about company any more and begin to fight amongst each other. At this age there are also typically one or two dark, more or less brightly circles occelly in the back part of the dorsal fin. Slowly the attractive colour of a adult is appearing