Dragon eels mate in the late summer when water temp is very warm, for what I discovered in this is, it is difficult to accommodate the eels with a study temp that has to be perfect and stable for weeks on end for to my knowledge, none every mated in captivity.
Some years ago on person dragon moray laid eggs, but I was able to tell that his male never fertilized the eggs for as well, he never shown me both, so I no idea if he even had a pair of both were females. For as well, I learn later that his nitrate levels for eggs were dangerously too high, for as well, one would need to maintain their tanks nitrate levels at untraceable levels.
Dragon Moray Eels