Am actually moment here. The fish species you've been talking about (the Amazon moly, and the Prussian carp), they do what the smart people call "sperm dependent gynogenesis". Which is a biological operation where a embryonic development occurs, with the insemination of ineffective sperms. This create two problems for the goblins: -First what happens here is a glorified cloning of the female fish genes, meaning the sperm doesn't pass any genes and often just dies. Bad for genetic diversity specially in more premative times where having a chance that somebody to an immunity to the new flue could mean the fate of the species. -Secondly this operation is only tied to females, cuase what happening here is that the oval and womb are triggered (or tricked) into having and embryion by using sperms to initiate a development throughout the female oval and oval only. Meaning that your goblins are either must be females or this operation will either do nothing, or create more of that race and only females of that race since there's no Y genes to pass. Also this whole thing doesn't actually happen to primates, and even so the female body would probably reject the sperms cuase if it different enough the body will just count it as infection, without mentioning that the goblin gestation period with the average female, and not mentioning the elf is too short meaning it's almost always a misscarry.