First Record of Phyllobothriid Metacestodes in Chimaera monstrosa (Holocephali) and Oncorhynchus gorbuscha (Salmonidae): Novel Insight into Larval Topography and Ultrastructure

Scanning electron microscopy was used to study the scolex morphology of 3 morphotypes of metacestodes of the order Phyllobothriidea (Cestoda) from the spiral intestine of the North Sea rabbitfish Chimaera monstrosa and the intestine and gall bladder of the pink salmon Oncorhynchus gorbuscha. Transmission electron microscopy allowed a detailed examination of the ultrastructure of the tegument, unicellular gland cells, muscle cells, and calcareous corpuscles of metacestodes of different sizes from chimaeras. Based on our morphological data, we propose that the studied intestinal metacestodes from chimaeras and pink salmon belong to the type XV metacestodes of Jensen and Bullard, possibly related to members of the genus Clistobothrium Dailey and Vogelbein, 1990.