'Killed in vast numbers': Horseshoe crabs under threat from overharvesting

The crabs' blue blood is used to test vaccines, saving millions of lives - but there are synthetic alternativesThey are some of the most spectacular images currently on display at the Wildlife Photographer of the Year exhibition in London. Huge pictures of weird creatures with golden carapaces and multiple legs scuttling across the seabed now adorn the walls of the city's Natural History Museum.The award-winning photographs, taken by Laurent Ballesta, could be visions of extraterrestrial lifeforms. In fact, they are horseshoe crabs that evolved hundreds of millions of years ago and which are some of Earth's oldest species. These living fossils thrive on the ocean floor where they root out worms, algae, and clams that they crush between their legs before eating. Continue reading...