There are some fish species which reproduce through parthenogensis. This may come in at least two froms, gynagenesis and hybridogenesis. One example of gynagenesis is with fish carrying monocha (M) and lucida (L) genes. Some females are triploid and carry MLL. These females will produce a triploid egg, also MLL. A diploid LL fish will release its L sperm in order to "fertilize" the MLL egg. There is actually no genetic transfer in this process, the sperm only stimulates the MLL egg. Once successfully stimulate, the egg activates and a new triploid MLL female (yes always female) fish is born. So where do males come from if all that is produced from this process is females? The normal diploid population, which is favored by diploid males. Therefore, there are two seperate populations. A diploid population of both males and females and a triploid population of all MLL female clones.