The waters off Borneo, the third-largest island in the world located at the geographic centre of Maritime Southeast Asia, harbour a high diversity of marine cestodes. We examined the tentaculariid species collection of the large-scale sampling endeavours in Malaysian Borneo between 2002 and 2008. Our study resulted in reporting the tentaculariid fauna of the region with greater detail, describing two new species, and erecting a new genus, Nybelinia pseudafricana n. sp. and Homeokotorella anterioporus n. gen., n. sp. A comparison of N. sphyrnae Yamaguti, 1952 from Malaysian Borneo, Australia, New Caledonia, and Japan revealed the synonymy of N. jayapaulazariahi Reimer, 1980 with N. sphyrnae. Remarks are provided for N. sphyrnae, N. aequidentata (Shipley & Hornell, 1906) Dollfus, 1930, Heteronybelinia estigmena (Dollfus, 1960) Palm, 1999, Tentacularia coryphaenae Bosc, 1802, Kotorella pronosoma (Stossich, 1900) Euzet & Radujkovic, 1989, and Kotorelliella (abbr. Ko.) jonesi Palm & Beveridge, 2002 and new host records are established for N. aequidentata and Ko. jonesi. Nybelinia aequidentata is reported for the first time from this region. Since most of the trypanorhynch species, including the tentaculariids, reported so far off Borneo are the same as those recorded off Indonesia, it seems that the trypanorhynch fauna of Borneo resembles the one from the Indonesian waters including to date 21 species (36%) of a total of 58 known tentaculariid species and 86 species (26%) of a total of 335 valid trypanorhynch species. These results allow us to better understand the species diversity of the tentaculariid trypanorhynchs off Malaysian Borneo.
Southeast Asia, Borneo, Tentaculariidae, elasmobranchs, new synonymy, new species, new genus