The male anglerfish undertakes an extraordinary mating process in the deep ocean. The tiny male must locate a female many times his size and, once found, bites her skin. Their bodies then merge as their circulatory systems join, making him a permanent part of her. He receives nutrients from her blood and supplies sperm when needed, ensuring the species continues in an environment where finding a mate is nearly impossible. His unique immune system, lacking certain key genes, prevents rejection du

From 2,600 feet below, the first footage of mating anglerfish, the female "resplendent with bioluminescent lights and elongated whisker-like structures." Full video via Science: bit.ly/2FYcXIs. | California Academy of Sciences