The coelacanth—a giant weird fish still around from dinosaur times—can live for 100 years, a new study found. These slow-moving, people-sized fish of the deep, nicknamed a “living fossil,” are the opposite of the live fast, die young mantra. These nocturnal fish grow at an achingly slow pace. Females don’t hit sexual maturity until their late 50s, the study said, while male coelacanths are sexually mature at 40 to 69 years. And maybe strangest of all, researchers figure pregnancy in the fish lasts about five years. Coelacanths, which have been around for 400 million years, were thought extinct until they were found alive in 1938 off South Africa. Scientists long believed coelacanths live about 20 years. But by applying a standard technique for dating commercial fish, French scientists calculated they actually live close to a century, according to a study in Thursday’s Current Biology. Coelacanths are so endangered that scientists …