Bull. nat. Hist. Mus. Land. (Zool.) 65(2): 133-153 



Issued 25 November 1999 



Nybelinia Poche, 1926, Heteronybelinia gen. 

 nov. and Mixonybelinia gen. nov. (Cestoda, 

 Trypanorhyncha) in the collections of The 

 Natural History Museum, London 



HARRY W. PALM 



Marine Pathology Group, Department of Fisheries Biology, Institut fur Meereskunde an der Universitat Kiel, 

 Diisternbrooker Weg 20, D-24105 Kiel, Germany 



SYNOPSIS. With a total of 43 adequately described species, the cosmopolitan genus Nybelinia is the most species-rich genus 

 within the order Trypanorhyncha. As an initial part of a revision of the genus, the present study was carried out to examine 

 unidentified and identified Nybelinia specimens deposited at The Natural History Museum London. A total of 1 7 different species 

 was found, four new species are described and 2 new genera, Heteronybelinia gen. nov. and Mixonybelinia gen. nov., are erected: 

 Nybelinia aequidentata (Shipley & Hornell, 1906); N. africana Dollfus. 1960; N. jayapaulazariahi Reimer, 1980; N. lingualis 

 (Cuvier, 1817); N. riseri Dollfus, 1960; N. sakanariae sp. nov.; N. schmidti sp. nov.; N. scoliodoni (Vijayalakshmi, Vijayalakshmi 

 & Gangadharam, 1996) comb, nov.; Nybelinia sp.; Heteronybelinia elongata (Shah & Bilqees, 1979) comb, nov.; H. estigmena 

 (Dollfus, 1960) comb, nov.; H. heteromorphi sp. nov.; H. minima sp. nov.; H. robusta (Linton, 1890) comb, nov.; H. yamagutii 

 (Dollfus, 1960) comb, nov.; Mixonybelinia beveridgei (Palm, Walter. Schwerdtfeger & Reimer, 1997) comb. nov. and M. 

 southwelli (Palm & Walter. 1 999) comb. nov.. Tentacularia scoliodoni is transferred to the genus Nybelinia. Nine new locality and 

 1 5 new host records were established. The adults of Heteronybelinia estigmena and H. yamagutii are reported for the first time. 

 It is proposed that the morphological variation within the different species is much higher than considered in the recent literature. 

 Many species within the genus have a world-wide distribution pattern and a low host specificity, both in their fish second 

 intermediate/paratenic hosts and in their final hosts. 



INTRODUCTION 



Trypanorhynchs are cosmopolitan marine cestodes and mature in 

 the stomach or the spiral valve of marine elasmobranchs, while their 

 postlarvae are parasitic in teleosts and invertebrates, with the first 

 intermediate hosts being crustaceans (Palm, 1997a, Sakanari & 

 Moser, 1989). Within the order Trypanorhyncha, the genus Nybelinia 

 Poche, 1926 is particularly difficult to study. Palm et al. (1997) 

 listed 43 adequately described species while leaving 4 as species of 

 uncertain status. Jones & Beveridge (1998) added a further species, 

 N. queenslandensis, and Palm & Walter (1999) described N. 

 southwelli, and synonymised Nybelinia dakari Dollfus, 1960 and N. 

 herdmani (Shipley & Hornell, 1 906) with N. perideraeus (Shipley & 

 Hornell, 1906) and Kotorella pronosoma (Stossich, 1901) respec- 

 tively. Thus, with a total of 43 adequately described species, the 

 genus Nybelinia is the most species-rich genus within the order 

 Trypanorhyncha. 



In contrast our knowledge of their biology is poor. The first 

 intermediate hosts are unknown and the occurrence of postlarvae in 

 marine plankton (Dollfus, 1974) is enigmatic. Postlarvae of these 

 robust worms are found in unusual sites such as the human palatine 

 tonsil (Kikuchi et al., 1981) as well as in anadromous Lampetra 

 japonica, 1000-3000 km away from the sea in the Amur river 

 (Shulman, 1957). Additionally, members of the genus Nybelinia 

 infest the fish flesh (Oshmarin et al., 1961, Palm, 1997b), and 

 parasitic infestation of the musculature of commercially important 

 fish species causes heavy losses to the fish processing industry 

 (Arthur et al., 1982, Deardorff et al., 1984). 



One of the biggest problems for taxonomic work within the genus 



Nybelinia, apart from incomplete original descriptions, remains the 

 lack of information on material deposited in museum collections. 

 The genus has not been revised since 1942, and due to the morpho- 

 logical similarity of several species, many Nybelinia specimens 

 found have not been identified to species level, and consequently 

 have been deposited as Nybelinia sp. Additionally, several species 

 descriptions are based on single specimens. 



The present study was carried out to examine unidentified species 

 of Nybelinia deposited at The Natural History Museum, London. 

 Measurements and drawings of most specimens are given as verifi- 

 cation of the identifications made. Beside the establishment of new 

 host and locality records, species identifications provide further 

 insight into the zoogeographical distribution. The comparison of the 

 scolex measurements with those from original descriptions allows 

 comments to be made on the level of intraspecific morphological 

 variation of some Nybelinia species, data which are necessary for 

 further taxonomic studies within the genus. The description of adult 

 specimens allows comparative investigations on strobilar morphol- 

 ogy within the genus. 



MATERIAL AND METHODS 



Standard measurements and drawings of the scoleces of Nybelinia 

 specimens deposited in the Parasitic Worms Division, The Natural 

 History Museum, London (BMNH), were made using a Leitz Wetzlar 

 Dialux 20 microscope with an ocular micrometer. Special attention 

 was given to unidentified specimens deposited simply as Nybelinia 

 sp., while other deposited and identified material was also exam- 



© The Natural History Museum, 1999 



