Written by Russell McAndrews
At present the Victoria Species Survival Plan maintains approximately thirty “species” at numerous sites across the nation. Distribution is carefully tracked as population levels in-country build. Funding pending will enable the refurbishing of a fisheries station on the Kenyan shores of the lake. To be known as the Kisumu Sorting and Breeding Center For Endangered Fishes, the government of Kenya has been very supportive of the concept and preliminary work. A recent assessment of total extinctions to date place losses at 40-50%. The rescue of two important pre-perch food fishes (Labeo victorianus and Oreochromis esculents), is identified as a priority. Research is on-going at three facilities around the lake in Uganda, Tanzania and Kenya. As conditions and fishes shift, researchers too must shift to different subjects or different areas. Lake-side conservation efforts will begin at Kisumu which is to have many small aquariums for sorting of collected fishes. Several large breeding ponds, water treatment had storage systems, and a larval hatchery and culture area sums up the site.
Within captive breeding stock we hope to attain 200 wild individuals for founder stock of each species. Ideally, three or more populations of each species per area will be set up to mitigate the damage of a site-wide disaster. This will also facilitate genetic diversity through the rotation of males from one population to another. Unfortunately, we may yet find that what we have is not what we thought it was. Early work done with electro phoresus seems to have thrown us another curve. It was hoped that in the near future populations would be sampled and verified by protein mapping. Unfortunately, it now appears that there is so little variation that the Haplochromini (tribe of Haplochromis-like spp.) will supply many more questions than answers. Until such time as a new means of identification can be developed, records and a policy of isolation will suffice. Without excellent records we will be unable to combat gene pool contamination as an entire population would be suspect. Eventually all populations will be verified this opening the way to rotate males among confirmed populations thereby recovering any loss of genetic diversity.
Long-term maintenance of any species is difficult, indeed impossible to fully perceive. The very nature of the program is to see these precious populations outlast their keepers and live on hundreds of years into the future. A national network of public zoos and aquaria is growing, but most have very little space and less funds. These organizations are jumping in and doing what they can, sadly the resources available are less than optimum. Many serious tropical fish hobbyist have as good or better facilities in areas conveniently local to existing Captive Breeding Program sites. In many such cases there people are more than competent and eager to serve. Resources and participation would increase many-fold if selected hobbyists were contacted for their support. This is the sort of open-minded commitment to conservation biology that the coming decade will require of all mankind. The amateur biologist and today’s aquarists will eventually learn that they must keep a ledger to give permanency to their observations, although it’s not the only means of doing so, it is the simplest.
These cichlids are maternal mouth brooders, after spawning the male takes no interest in his progeny. Most if not all will eat their own young. Brooding females must have some place to retreat to out of sight of the male. Although it is tempting to remove the female at this point, these fish will set up a RIGID hierarchy within the confines of an aquarium. Some stress is bound to be felt in the case of prolonged separation but the real problem is that upon reintroduction her spot in the pecking order will have been filled, death is the all too frequent result. If kept in pairs, invariably the female will get murdered. This is primarily due to the male’s lack of distractions.
The best method of housing and propagating these fish is in groups with at least two males and several females. The introduction of a second non-cichlid species is useful as dither fish (social shock absorber). Barbs and danios are inexpensive, hardy and harmless. Interactions of this type aid in stimulating a more natural environment by providing a most dynamic set of stimuli. Do not remove females from the colony until eight days post spawning, this allows the eggs time to hatch and permit’s the stripping of newly hatched fry and the immediate reintroduction of the female to the colony. Higher numbers of fry are achieved if the zygotes are removed soon after hatching, additionally the female turn over spawns more quickly. After a given male has spawned with all females he should be removed to allow another make to take the dominant position. Sibling to sibling spawn loses some genetic diversity but this damage is repairable with the eventual verification and mixing of other gene pools, the males will be rotated.
It is useful to furnish rock, plants or pieces of pipe for hiding places. Many Victorians prefer a floating plant cover. This is somewhat inconsistent with the use of salts but many are tolerant of a trace amount of magnesium sulfate (Epson Salt), potassium chloride and sodium chloride. I find that medium size, crowed tanks with only floating plant cover for décor work well, un-crowded tanks must provide ever more cover. Be advised that these fish are quite capable jumpers. This is usually going to take place at the corners of the tank. Although many of these fish are found in marshy, turbid waters and tolerate nitrates well, the open water species do not. Activated carbon should be used with these, typically the most endangered species.
There are many levels of aggression which can sometimes be correlated to the fish’s trophic (feeding) preferences. For the most part these cichlids are gregarious and will coexist if given proper room and cover. No special diet is required; in most cases flake food is safe and more than sufficient. Allowing the fish to feed in a natural way, such as by grazing on live vegetation will help to preserve the natural phenotypic diversity. Specific diets such as snails might be used if studying pharyngeal bone development. Understanding trophic competition is key to our understanding of these fishes.
We need publicity and money. Progress at present is too slow, funding is even slower, our one NOAA grant was for the purpose of assisting the nature and extent of the problem. New information suggests that we have only discovered perhaps half of the species present that there is in fact an entire complex of dwarf Haplochromines that were not brought up in yesterday’s large meshes as well as newly discovered “species” around every point. The total number of species is unknown and estimates run from 300-1000, with the recent surveys giving the higher estimates. The limno logical survey is winding down but as yet we have no new money to cover what remains to be done; acquisition, housing, reproduction, distribution, fund raising and education.