Sea slugs have 'disposable penis'
A sea slug that is able to detach, re-grow and then re-use its penis has surprised scientists. Japanese researchers observed the bizarre mating behaviour in a species called Chromodoris reticulata, which is found in the Pacific Ocean. They believe this is the first creature known that can repeatedly copulate with what they describe as a "disposable penis". The study is published in the Royal Society's journal Biology Letters.