SAN DIEGO — A 45-year-old Asian elephant named Devi who had lived at the San Diego Zoo since 1977 was euthanized on Thursday after zoo officials said her health had declined. “Devi was beloved at the San Diego Zoo and she will be sorely missed by all of us who cared for her on a daily basis,” Ann Alfama, a wildlife care supervisor at the zoo, said in a statement. “We find some comfort in knowing that she leaves an amazing legacy as an ambassador for her species.” The elephant had received hydrotherapy, physical therapy and stem cell therapy to alleviate age-related ailments but her mobility co…