British Wildlife of the Week: Lamprey
At the bottom of a freshwater stream in Britain, a thin, elongated fish undulates through the water. It looks a bit like an eel, but closer examination reveals it is something much different, and much stranger. It only has a single nostril (on the top of its head) and its large suctorial mouth is bristling with sharp, inward-pointing teeth of varying sizes, arranged in neat concentric circles.