Okay... no need to get all, well, nevermind. Anywho. As for your mertensi queries for whatever you're developing. Some private keepers do keep such records. There are private hobbyists in the USA, Germany, UK, etc that have done very well with the species. As for guidelines, there really is no formula. What works for some may not work for others. That can be any amount of different factors. Placing of housing, diet, temperature choices, water access and quality, nesting material. Simplest works best, but even if you have a pair, it is not guaranteed. Animals always don't get along, bullying or preference of same sex, etc. Once the housing is set-up, dialed in, it is the animals that will tell you if you succeeded or not. Could be something simple as furnishings or hard like mass (substrate). Offering different temperature ranges lets the animals choose what will support them. Even what has worked for, oh, I don't know, 50 mertensi, 1, may flip you the bird and disagree. Always good to start with younger animals, 1.2, 1.3, 2.3, etc works best. Less issues arise amongst them. Until the males or females choose their own gender. Always good to have multiple enclosures and animals for moving/swapping around. Just my .02¢