Redescriptions and new records of species of Otobothrium Linton, 1890 (Cestoda: Trypanorhyncha).

Redescriptions are provided for five incompletely described species of Otobothrium Linton, 1890: Otobothrium alexanderi Palm, 2004 from two species of carcharhinid sharks, Carcharhinus cautus (Whitley) and C. melanopterus (Quoy & Gaimard) at three localities off northern Australia; O. australe Palm, 2004 based on material collected from the type-host and type-locality and from six additional myliobatid and carcharhinid host species off Western Australia, the Northern Territory and northern Queensland; O. insigne Linton, 1905 from Rhizoprionodon terraenovae (Richardson) and Sphyrna tudes (Valenciennes) in the Atlantic Ocean off Senegal and the Democratic Republic of the Congo; O. mugilis Hiscock, 1954, previously known only from larval stages, based on adults from five sphyrnid and carcharhinid definitive host species off northern Australia and Malaysian Borneo; and O. penetrans Linton, 1907 from material collected from two species of hammerhead sharks (Sphyrnidae) in the Red Sea off Jordan and the Indian Ocean off Western Australia. Additional host and locality records are added for the type-species, O. crenacolle Linton, 1890 and for O. carcharidis (Shipley & Hornell, 1906). Two descriptions are provided for Otobothrium spp. treated here as Otobothrium sp. 1 from C. melanopterus off northern Australia and Otobothrium sp. 2 from Sphyrna zygaena (Linnaeus) in the Gulf of California, Mexico.