Notomegarhynchus navonae n. gen. and n. sp. (Eucestoda: Tetraphyllidea), from skates (Rajidae: Arhynchobatinae) in the southern hemisphere

• Language: unknown
• Published: 2002
• Subjects: parasitology; article; cestode; electric fish; life cycle; morphology; nonhuman; Notomegarhynchus navonae; parasite identification; taxonomy; Animals; Argentina; Cestoda; Female; Histocytochemistry; Intestines; Male; Microscopy; Electron; Scanning; Skates (Fish); Terminology; Arhynchobatinae; Atlantoraja castelnaui; Bathyraja eatonii; Bathyraja maccaini; Echeneibothriinae; Eucestoda; Myzorhynchus; Phyllobothriidae; Rajidae; Tetraphyllidea; Antarc*; Antarctica
• Online Access: https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00223395_v88_n2_p340_Ivanov; https://hdl.handle.net/20.500.12110/paper_00223395_v88_n2_p340_Ivanov

Notomegarhynchus n. gen. (Eucestoda: Tetraphyllidea) is proposed to accommodate Notomegarhynchus navonae n. gen., n. sp. from Atlantoraja castelnaui in Mar del Plata, Argentina. Nototmegarhynchus shetlandicum n. comb. from Bathyraja eatonii and B. maccaini in South Shetlands region, Antarctica, is a second species in the genus. Notomegarhynchus belongs to the Echeneibothriinae within the Phyllobothriidae. It can be distinguished from all other tetraphyllidean genera by the structure of the scolex in form of a massive myzorhynchus consisting of a proscolex and an apical organ, both of which are nonretractable and noninvaginable; in addition, there are 4 pedunculated and nonloculate acetabula. Notomegarhynchus shetlandicum is differentiated from N. navonae particularly in details of acetabular and myzorhynchus morphology, arrangement of testes, and shape of eggs. The inclusion of Notomegarhynchus in the Echeneibothriinae requires emendation of the diagnosis of the subfamily to include taxa possessing postvaginal testes. In addition, new terminology is proposed for distinct regions of the scolex.