Editor’s Note: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, together with the solutions. Rolex’s Perpetual Planet Initiative has ...

Add Yahoo as a preferred source to see more of our stories on Google. Editor’s Note: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, ...

(CNN) — Pygmy seahorses, about the size of a fingernail, are some of the smallest vertebrates in the world. First discovered in 1969, little was known about the creatures. But in the early 2000s, ...