AAGB

Some notable observations on the breeding of Ctenopoma weeksii

by Michael Muller, IGL

I remember the Spring meeting 1994 at Alzey with pleasure for two reasons. Firstly, I met the main speaker, Frank Schaefer with whom I had already corresponded. Frank spoke about the group of fish which made me become a member of 'ZAG Labyrinthfish' . I had been engaged for about 5 years in breeding 'Peacock-eyed Bushfish',Ctenopoma weeksii which was then still called C.oxyrhynchum. The talk Frank gave and the questions that it posed, made me write this article.

In the years of breeding this fish, I made some notable observations which I must definitely mention. I had a group of 3 males and 4 females in a community tank of about 450 litres. This aquarium was supposed to have an Asiatic character. I was at that time a lover of large barbs so I had 11 Puntius everetti, 7 Puntius filamentosus, 6 Puntius arulius and 5 Mystus catfish. But over a period, fish from other parts of the world found their way into the aquarium. First south American catfish (Ancistrus, Dasyloricaria) and eventually, Bushfish from Africa. These fish were given to me by a member of our group and with them, the foundation of my hobby of anabantoids was laid. Later Paradisefish (Macropodus opercularis) kissing gouramis (Helostoma teminckii) and Cimbing Perch (Anabas testudineus) were added.

When I got the Bushfish, they were about 5 cm long and during 1 year they grew into pretty, 12 cm long fish. The genders could be easily differentiated. The females were always a little fatter and on the males you could see the 'thornfields' behind the eye and on the root of the tail if you really looked. After I observed their courtship and spawning behaviour in the community tank, I decided to breed them in earnest. The water values were the same as Berlin tap water and the surrounding countryside; 17-24 dGH, 7-12 KH, pH 7-8. The aquarium was not specially heated, it stood against a chimney breast and the temperatures were 21-25C.

About 100 litres of he water was changed on average, every 3 weeks. The fresh water came straight from the tap and for a time the temperature went down to 12-16C for a short time. Only just after the water change was the aquarium heated. I had the impression that my big barbs and the Bushfish showed greater vitality and better willingness to spawn thanks to this procedure. Only the Kissing gouramis resented the water change every time but even though they suffered from the sudden fall in temperature, they always recovered.

A male and female who were ready to spawn were fished out of the community aquarium and put in a thickly-planted 150 x 50 x 40 cm tank. During the first years, all went normally, as one reads about it in the popular literature. Especially, one has to mention that they didn't always spawn immediately, at best it happened the next day and at worst, after 3 months. Trials with different temperatures showed that spawning nearly always took place when the temperature was about 24C.

The spawning started between 1800 and 2000 with false pairings and finished between 2200 and 2400. The pair was then fished out and returned to the community tank. Only about 40% of the eggs were fertilised and because of that, I had to use an antibiotic against fungus. I cannot say anything about the timing of eggs or larvae, as I made no notes and I didn't think it was of interest to me.

The main problem, as usual with anabantoids, was what food to use on the young fish. The aquarium in which the fish were raised was thickly planted and each free-swimming young fish found for itself, the darkest place under a leaf and nothing could persuade it to come away! Only when live food was introduced, which danced up and down in front of the little fish's mouth, was it tempted to feed. I always fed them slipper animalicules (Paramecium) or finest sieved pond plankton. After a week, the young slowly started to find food for themselves and they were also fed some 'Mikro'. Even if they refused dried food, I put a little in each day and when they were about 1 cm long, they greedily ate large quantities of everything, including dried food and they grew very quickly with frequent water changes. the temperature in the aquarium was a constant 24C. I mention this because a change to higher temperatures led to disaster, even if other breeders could not confirm this. On one occasion, I had about 50 young Dasylocaria filamentosa which were about 2 cm long and which I put in with some young Bushfish which were about half this size, because I had run out of room. I now slowly raised the temperature to 26-28C and lost about 90% of the Bushfish. Later attempts to raise the temperature also led to high losses.

During the later years, I observed a lot of variations from 'normal behaviour' in some of the pairs. The following observation may have something to do with the increased age of the fish. It started with a late spawning at night. I felt it was very late and that the fish wouldn't finish spawning until after midnight so I left the fish together. The next morning, I noticed that there were fewer eggs left and that they fell upon the eggs and gobbled them up greedily. I am now coming to the question raised in Frank Schaeffer's talk about egg eating by free-spawning Bushfish. Personally, I could not say if this applies to all Peacock-eyed Bushfish. For spawning, I always fished the pair out of the community tank and I did not know if I'd put them together earlier but, of course, I always used the best and prettiest fish to breed with. The 'egg-gobbling' was seen more and more, the older the fish became.

Another abnormal behaviour that I observed in the later years was also repeated. The spawning started just as in other observations with the male pushing into the side of the female. After the fish had got rid of about one-third to one half of her eggs, the male started to get disinterested. It went so far that he disappeared into the thicket of plants and could not be persuaded out again. After that scenario, the female became more and more active and later even aggressive. Now the male was being butted and then chased very roughly through the aquarium. Because I feared for his life, I put both fish back in the aquarium with the other fish. Maybe I should have paired the older female with a younger male. After all, I had fish from other spawnings.

I had no time for further experiment because of the political events of 1989 and I had to pull back a bit on my hobby. I gave the fish to an acquaintance and it does not look as though I could take up the breeding of Bushfish again in the near future. Even so, I should be pleased to see a greater interest in these rather neglected anabantoids.

Translated from  'DER MAKROPODE' by Mrs R. Armitage (Wyneken) and reproduced with permission

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