Two New Species of Aporhynchus (Cestoda: Trypanorhyncha) from Deep Water Lanternsharks (Squaliformes: Etmopteridae) in the Azores, Portugal

Abstract

New collections of cestodes from the spiral intestines of the lanternsharks Etmopterus spinax and Etmopterus pusillus off the island of Faial, in the Azores, Atlantic Ocean, have yielded 2 new species of trypanorhynchs belonging to Aporhynchus. Both species share the distinctive lack of all elements of the rhyncheal system that are characteristic of this genus. The identity of Aporhynchus norvegicus is clarified to allow it to be distinguished from A. menezesi n. sp., which also parasitizes E. spinax. This new species differs conspicuously from its congeners in that its mature and gravid proglottids are wider than long, rather than longer than wide, and also in its lack of spinitriches on the scolex. Aporhynchus pickeringae n. sp., the new species from E. pusillus , differs from all of its congeners except A. norvegicus in that it is a relatively delicate worm with relatively fewer testes. It also possesses fewer proglottids and a wider pedunculus scolecis than does A. norvegicus. Sections through the scolex of A. menezesi n. sp. support use of the term bothriate, rather than difossate, in reference to the scolex configuration of some trypanorhynchs. A key to the 4 species of Aporhynchus is provided.