You may have heard how some anglerfish reproduce via the males fusing their bodies to the females' until they essentially become one; the male loses his eyes, fins, teeth, and some internal organs and, from that point forward, lives off of the female, providing sperm when she's ready to spawn. Those fish are members of the suborder Ceratioidei, [or] deep sea anglerfishes, in which some species are known to reproduce by that means. Still, that's not the norm for those fish—scientists have so far only found parasitic males in 5 of 11 ceratioid families. (censored because scary)