Thanks, I had wondered if since they had two hemipenes if each connected directly to it’s own testis. I had to actually look up if they had two testis or ovaries and found an interesting thing that the right one is supposed to always be closer to the head than the left.

To take the chimera theory a step further (and as far as I know it's just an unproven theory of what MIGHT be going on with the paradox animals), what about the 50% of the time where the siblings would be different genders? Any reason those babies couldn't be expected to hatch? Suppose it would depend on the particulars of who got what parts if they could reproduce as either sex.