The rod-like lure on the head of a female anglerfish attracts prey using bioluminescence.

References

"The female anglerfish is squat and lumpy in shape, equipped with many needle-sharp teeth in her huge mouth, and a small luminous lure like a fishing-rod (hence her name) by which she attracts prey fish within reach of her jaws." (Foy and Oxford Scientific Films 1982:52)

Book
The grand design: Form and colour in animalsJanuary 1, 1970
Sally Foy