Nybelinia Poche, 1926 (Cestoda: Trypanorhyncha) from the Moçambique coast, with description of N. beveridgei sp. nov. and systematic consideration of the genus

Abstract

A total of 247 specimens from 16 fish and one cephalopod species from the coastal waters of Mocambique was investigated for infestation with trypanorhynch cestodes. Postlarvae of six different Nybelinia species could be identified: N. africana, N. anthicosum, N. beveridgei sp. nov., N. gopalai, N. robusta, and N. yamagutii. All represent new locality records. In all, 27 new host records were established. N. yamagutii and N. africana were the most abundant parasites, infesting seven and six of the examined fish and cephalopod species respectively. The squid Todarodes angolensis and the teleost Ventrifossa nasuta had the highest prevalence of infestation (79 and 75 % respectively). Whereas the teleost Saurida undosquamis was infested with four different Nybelinia species, most hosts harboured a single species only. To date, a total of 47 different Nybelinia species are known. Of these, 43 are considered to be adequately described. N. beveridgei sp. nov. can be distinguished by its large scolex and its homeoacanthous heteromorphous tentacular armature and its characteristic basal armature. For further taxonomic work and to simplify Nybelinia identification, a new subdivision of the species is proposed, based on the following 3 characters: metabasal tentacular armature; tentacles with or without a characteristic basal armature; and size of basal hooks in comparison to metabasal hooks. A cladistic analysis revealed no further insights into the phylogeny of the genus.