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Experiences with Ctenochromis sauvagei

By , 1998. printer
Published
Mary Bailey, 2001

Classification: Captive maintenance, Lake Victoria.

Ctenochromis sauvagei male Ctenochromis sauvagei adult male in breeding dress. Fish and Photo by Mary Bailey.

My interest in Lake Victoria cichlids dates from my fish-keeping beginnings in the early 1970's, when by chance, and ignorant of their rarity in the hobby, I acquired and bred a pair of Astatotilapia nubila. Later on, when the devastation inflicted by the Nile Perch (Lates niloticus) on the haplochromine populations of the lake became evident, I was eager to join in any captive breeding project that might develop, but (in common with other hobbyists in the UK) was frustrated by a total unavailability of breeding stock. Fishes were being kept and studied at various scientific institutions here and abroad, but not released to hobbyists, even serious hobbyists who were anxious to contribute their expertise to a worthwhile project.

Then in the summer of 1990, I received a telephone call out of the blue from a colleague of Dr. George Turner at the University of Bangor in North Wales. The British Cichlid Association Species Controller had been approached for the names of persons who might be interested in having some Ctenochromis sauvagei fry, and mine had been put forward. I accepted eagerly and was soon in possession of 20 fry from two breeding lines.

Because the whole affair was very sudden, and the fish-house already fairly fully occupied, I had no choice but to keep the two batches of fry together and let them interbreed according to their own inclinations. It might, perhaps, have been preferable to have kept them separate and carefully produced my own breeding lines, but my facilities are limited and such a project would have meant devoting them exclusively to the sauvagei, which I felt unable to do for a number of reasons. In any event I have so far produced several hundred fry which have included only two runts and a single spinal deformity, results which compare favorably with experiences with wild caught mbuna. The spawning pattern seems to involve all females ripening virtually simultaneously, so that any batch of fry being raised probably represents a well mixed gene pool. It remains to be seen whether any problems attributable to inbreeding will occur in subsequent generations.

Obviously my first task was to grow out the fry, which were only a few weeks old. This presented no particular problems. They were willing enough to take any foods offered and grew on rapidly despite a tendency toward shyness, which has been observed in various other species of Victorian cichlids. This may stem from the fact that the turbidity of their natural waters provides a degree of natural concealment which we can hardly reproduce in captivity, though one would expect any nervousness in clear water to be lost by fishes which have never known anything else.

It soon became obvious that the original lot included two runts (which eventually died unaided) and a preponderance of males (13 in all). I had to decide at this stage whether to intervene in natural mate selection by removing the majority of the males before a major war broke out, or to leave matters as they were and see how things developed. Again constrained by considerations of space and wishing to have the best opportunity of crossing the two breeding lines, I decided on the latter course. I reasoned that if the males did decide to engage in open warfare, they would be unlikely to have the time or inclination to harass the females, whereas one or two males might well have done so. The strategy has proved most successful. In a 122 x 38 x 46 cm tank decorated with a few large rocks and pieces of bog-wood (both with clumps of Java fern attached), I have four males holding small (15-20 cm. diameter) breeding territories and showing full color, while the spare males and females form a loose shoal in the open water about 10 cm. above the substrate. The non-territorial males show muted coloration and occasionally frayed finnage, but there have been no other injuries, and I have never seen any fish, male or female, hanging near the surface to avoid harassment. When a female is ripe the territorial males become quite frenzied in their display to her and each other. The males' territories are extended somewhat, vertically as well as laterally, so that the shoal of non-breeders is driven slightly higher above the substrate. There is no chasing except when territorial infringements occur and then only to the boundary of the territory. Display is what I would term typically haplochromine: lateral display of the body and finnage, including the anal ocelli, accompanied by violent quivering.

I have not witnessed actual spawning, but assume this takes place in the pit which forms the heart of the male's territory. Nor have I been able to ascertain whether spawning is monogamous or polygamous, although pre-spawning females appear to be most interested in the most dominant (and resplendent) male of the four. There has been no sign of females being harassed after spawning or at any other time.

The first spawning took place after maintaining the fish for about a year, by which time they were fully grown (10-12 cm. SL for males, 7.5-10 cm. SL for females). There was no sign of precocious breeding, and there has been none in their offspring, many of which have been grown out to 5 cm. or so by which size a few young males are starting to color up and becoming moderately territorial. This contrasts markedly with my A. nubila, where at a similar size (5 cm.) in an ultimately larger species (15-18 cm. for males), every male was highly colored and practically every female was brooding!

Early attempts to move brooding females to separate quarters all resulted in the eggs being spat out in the bowl used to remove them from the tank, if not previously spat in the net. Interestingly, on two occasions the clutch contained pieces of gravel of approximately the same size and color as the eggs themselves, evidencing that spawning probably does take place in the pit dug by the male. Some fry were raised artificially from the ejected eggs in order to ensure a new generation, but subsequently females were left to brood for 16-18 days, at which stage the fry are free-swimming, even though normal release is after 20-23 days (at ca. 27у). It is far less trouble to deal with fully developed fry spat out in the net or bowl! But by the third or fourth brood in each female, the problem had reversed with females not only retaining their fry when netted, but refusing to release them at the appropriate time and having to be stripped at 25-28 days for their own sake as well as that of their offspring. I now remove females a few days after spawning so that they have time to settle in their brooding quarters and thus have the confidence to release the fry at the correct time; I've had no further problems with eggs being ejected. This is the only mouth-brooder among the many I have bred where egg ejection upon netting has even been a problem. Brood size in adult females is small relative to body size with 30-40 fry being a good-sized brood.

Little information is available on the natural habitat and behavior of Ctenochromis sauvagei due to the aforementioned turbidity of the waters of the lake coupled with bilharzia acting as a deterrent to underwater researches. It is purportedly found over sandy or shingly substrates and is known to be primarily a snail eater, although also consuming other aquatic organisms (Greenwood, 1980). I have dropped fairly large quantities of Malayan burrowing snails into my sauvagei tank where they have been mouthed and apparently rejected as inedible. The tank, however, has failed to become infested with these pests, so I can only assume that the fish are in fact consuming them when no alternative easier food is available. Tanks in which larger fry are being reared are likewise free of these snails, which are regrettably otherwise rife in my tanks.

I have observed interesting flight/escape behaviors in Ctenochromis sauvagei. When any attempt is made to net adults (normal hiding places having been first removed) or fry above 2.5 cm. in length, two separate methods of flight are seen. Some individuals head for the surface, sometimes actually "pancaking" along it, while others bury themselves in the substrate (=gravel), where they may remain for some time. I have not been able to establish whether particular individuals favor one escape method or the other, and it does not appear to be sex-related. Brooding females do not employ either method, but skulk near any available cover or the end glass of the tank.

The possession of two quite different modes of flight suggest to me that either the species favors shallow water where both alternatives are readily available, or else that it spends time at different water levels. Its dietary preference, however, points to a bottom-dwelling existence, so I assume that the shallow water hypothesis is more likely.

In conclusion Ctenochromis sauvagei is an attractive and easily maintained species with no noticeable anti-social habits (except digging), which I unhesitatingly recommend to anyone who has the opportunity to keep it.

Ctenochromis sauvagei femalea Ctenochromis sauvagei adult male in breeding dress. Ctenochromis sauvagei females, the one in the background brooding young. Fish and Photo by Mary Bailey.

References (1):

Citation

Bailey, Mary. (August 15, 1998). "Experiences with Ctenochromis sauvagei". Cichlid Room Companion. Retrieved on December 16, 2018, from: https://www.cichlidae.com/article.php?id=101.

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