传染性鱼类癌症泛滥新英格兰湖泊

Genetic studies reveal rare example of identical transmissible tumors TIM APPENZELLER Lake Memphremagog stretches an idyllic 50 kilometers through woods and farmland from northern Vermont into southern Quebec. “That lake has great fishing … big lake trout, big salmon, big rainbow trout, a great perch fishery,” says Peter Emerson of the Vermont Fish & Wildlife Department. Its abundant brown bullhead catfish (Ameiurus nebulosus), however, are less enticing: Nearly one-third are spotted with an inky-black cancer. It’s a rare and strange form of the disease, a team of geneticists and fisheries biologists including Emerson shows in a study this week in Nature. Unlike most cancers, this one—a melanoma—is not an abnormal growth of each fish’s own tissue. …