Thursday, April 5, 2012
Groenke's Swordtail Breeding Program.
Groenke's method of producing fine fish was so exacting that I will both quote and summarize his suggestions. He started with culling. Groenke wrote, "Heavy culling is absolutely necessary.” He gives an example of what he means, “Within a 24 - hour period, three of my best females had young. There were 103 total. Thirty were culled out at once because they lacked the proper body color. During the next seven days, five more were culled out because they did not develop properly. At three weeks I culled out all the low fins. This left 48 hi - fins, Simpson and lyretail. Of these 48, about 10% to 15% will qualify as first class breeders."
Next, Groenke dealt with environment. He told of how he tried to duplicate the swordtail's natural environment. Groenke noted, "The swordtail, in its natural habitat, enjoys fresh clear running water. I use airstones very extensively. This increases the oxygen supply in the water and forces the fish to swim. The more they exercise, the more they eat; consequently, they grow faster. Airstones also help to expel gases. During the first four weeks of the fry's life, I use two or three airstones per 10 - gallon tank."
Groenke goes on to say that he used a power filter and a sponge filter on each tank and, during the first four weeks, changed one tenth of the water every other day on the fry. After a month, Groenke decreased the airstones, fed less and water changes became one tenth once a week. He commented that the first 4 weeks were the crucial time of development in raising fine fancy swordtails.
Groenke's feeding program could break the resolve of the most dedicated breeder. Groenke writes that, "The first week, the young fry continually have live baby brine shrimp from morning until evening. This means about three feedings a day as the brine shrimp live about four or five hours in the aquarium water. By the second week they have grown considerably and should be fed brine shrimp, live or frozen, every two hours or about eight times a day. At three weeks, I start adding some dry food."
At four weeks of age, the fry were still in the 10 gallon tanks in which they were born and, according to Groenke, it was now time to move them. He used 15 to 30 gallon tanks depending on the number of fry involved. His feeding program also changed. Groenke reported that he now employed a greater variety of dry food, along with tubifex worms, adult frozen brine shrimp, live baby brine shrimp and his own paste food. This menu was offered for the next four weeks and the fish were fed about six times a day. At the age of two months, Groenke wrote that his fish had achieved a two inch body size -- three inches if the tail was included. At this time, Groenke culled or sold everything but his future breeders.
Groenke gave these future breeders about three gallons of water per fish in a 30 - gallon aquarium. He also decreased the feeding schedule to three times a day. This decrease was based on Groenke's belief that it gave "the reproductive organs a better chance to develop." He wrote that he had "noted from past experience that some females which were force fed would not reproduce” and when he cut down on feeding, "within a few months they began to bear young." Groenke theorized that, "With constant forced feeding, much of the oxygen that is taken in by the fish is used to aid organs of digestion, and the result is that the reproductive organs get less oxygen and do not always develop properly."
Whenever anyone asks me for advice on raising fancy swordtails, I always give them a copy of Groenke's article. Few people can meet its ideal procedure, but it sure does set the bar at the level of a real challenge. The only place where I differ from Groenke is on water changes. I agree on the number of water changes for the young fry but I change a larger percentage – say 50-80%. On the sub-adults and adults, I also change a larger percentage of water than he did (80%) and change it more often (2-3 times a week). Of course, this assumes one has a good source of properly aged and treated water at the right temperature ready to go. Individual localities, fishrooms, schedules and/or water problems need to be considered when following this plan. The water must be chemically right and acceptable to the fish. What works for one person may not work for another. Proceed with caution.