First Report of an Adult Tapeworm (Cestoda: Diphyllobothriidea) in a Southern Sea Otter (Enhydra lutris nereis).

We present a novel case of an intestinal cestode infection in a southern sea otter (Enhydra lutris nereis). The cestode species Diphyllobothrium tetrapterum (syn. Diplogonoporus tetrapterus) was confirmed genetically. Stable isotope analysis of whiskers collected from the sea otter did not confirm the consumption of fish as the route of exposure.