In the warm waters of the Caribbean, long-spined sea urchins — inky black creatures resembling pincushions stuck with knitting needles — gobble up algae with their claw-like mouths. But when the sea urchins aren’t around, this algae will smother coral reefs, eventually causing the corals to die. That’s what happened in the early 1980s. A … Continue reading Parasites of the Caribbean: Study pinpoints cause of sea urchin die-off