A curled tail grips seagrass while a coronet cuts the waterline: the animal looks like an emblem borrowed from myth, yet its biology is stubbornly piscine. The illusion is persuasive. Seahorses belong to Hippocampus, a genus of ray-finned bony fishes, identified by gills, fins, and a skeleton of bony plates rather than by any kinship with horses.The stranger fact is sex. In syngnathid reproduction...More