Here's why:
* Species Specificity: Different types of plecostomus are actually distinct species. While they may look similar, they have evolved separate genetic pathways. This means their reproductive cells are designed to work with their own species.
* Hybrids: While it's not impossible for different species to produce hybrids, it's rare and usually results in offspring that are infertile or have health problems.
* Behavior: Even if fertilization occurred, the differences in their breeding behaviors and preferences might make successful reproduction unlikely.
In summary: It's much safer to assume that different types of plecostomus will not breed successfully. If you're looking to breed plecostomus, it's best to stick with fish of the same species.