A fish species called the armored rockhead poacher (Bothragonus swanii) carries a secret that has confounded marine biologists for decades: a deep, bowl-shaped hole in the middle of its skull. This bizarre anatomical feature has now been linked to an extraordinary form of communication. The rockhead poacher (Bothragonus swanii) in Oregon Coast Aquarium. Image credit: Rhinopias / CC BY-SA 4.0. First described by Franz Steindachner in 1876, Bothragonus...
