There is little research on eunuch eels, but the term simply refers to eels that are sterile. Eels are meant to reach sexual maturity, travel to their spawning grounds, and then die. But, some theorize that eunuch eels stay in freshwater, continuing to live and get bigger. It’s likely that sterile, long-lived eels will grow larger. Still, it’s unlikely that they will grow to monstrous sizes.