During this time leptocephali, in the presence of suitable currents, may disperse widely from the adult spawning area. Working on massive collections of larvae from 1905 to 1930, a Danish biologist, Johannes Schmidt, established the early life history of the European (Anguilla anguilla) and ...
"They have to come up to breathe," says Donna Hauser,a marine biologist (海洋生物学家) at the University of Alaska. "That's a more difficult job,and they have to find openings in the ice."(北冰洋的秋天到了。冰开始在水面上形成,使得白鲸很难找到开阔的地方出来呼吸空气...