Keeping your mate extraordinarily close—as in permanently fused to your body—has its advantages.
A mile or more down in the lightless ocean, deep-sea anglerfish search for partners. The 162 species of this Ceratioid suborder form odd couples: The males are dwarfed, the females many times larger (some three feet long). Yet they’re uniquely equipped to find each other.
The male’s outsize nostrils pick up the female’s waterborne pheromones. His well-developed eyes search for a spot of light: the bioluminescent lure on a stalk adorning the female’s brow. Ted Pietsch, a University of Washington ichthyologist, says the lures’ different shapes, pigment patterns, and flash patterns tell a male when he’s found a female of his species to hook up with.