DESCRIPTION OF THREE NYBELIN1A SPECIES 



8a 



129 



I 



Fig. 8a-b Kotorella pronosoma {Nybelinia herdmani). a. metabasal tentacular armature, external surface, b. basal tentacular armature, external surface. 

 Scale bars=10 um. 



proglottids: 71-85 in diameter). Testes encircle the female genital 

 complex (Fig. 9). Female genital complex median. 



Remarks. 



In 1906, Shipley & Hornell described Tetrarhynchus herdmani from 

 the alimentary canal of Himantura imbricata and Rhynchobatus 

 djeddensis from the Gulf of Mannar (Sri Lanka). However, only a 

 few measurements were given and the tentacular hooks were de- 

 scribed as being similar and of the same size (10 um) along the 

 tentacle. Southwell (1929a) cited Shipley and Hornell (1906) and 

 listed T. herdmani with T. perideraeus as a species with extremely 

 minute (practically equal in size) hooks arranged in spirals 

 (Southwell, 1929b). Pintner( 1930) re-described the type material of 

 T. herdmani and reported a homeoacanthous, heteromorphous arma- 

 ture. His description of the tentacles with about 10 small hooks per 

 row, tightly arranged and forming a mosaic on one side, was 

 emended by Dollfus (1942), who reported 14 um large hooks with a 

 large base. The drawings of Pintner (1930, Figs 67a-b') also give a 

 metabasal hook size between 10-11 um on the lateral (antibothridial) 

 and 10-14 um on the medial (bothridial) tentacle surface (7-8 um of 

 basal antibothridial hooks and 10-14 urn of basal bothridial hooks? 

 / Fig. 67a'and 67b'). Thus, the drawings of the tentacular armature 

 as given by Pintner (1930) correspond to the armature of the type 

 material as described above. Our scolex measurements of the types 

 oiN. herdmani also correspond to those given by Pintner (1930) and 

 Dollfus (1942) for N. herdmani (Table 1). 



Euzet & Radujkovic (1989) re-described Kotorella pronosoma 

 (Stossich, 1901) from the spiral valve of Dasyatis pastinaca L. from 

 the Mediterranean Sea. Though the absolute values of their scolex 

 measurements are about l/3 rd smaller than those given for Nybelinia 

 herdmani (Table 1), the scolex and bulb ratios are very similar (see 

 above). The hooks size as given by Euzet & Radujkovic (1989) for 

 K. pronosoma is also about l/3 rd smaller (hooks size between 5-8 

 um). Campbell & Beveridge (1994, Figs 7.48-7.50) gave additional 



figures of the scolex and tentacular armature of K. pronosoma with 

 a metabasal/apical hook size of about 10-11 um (bothridial and 

 antibothridial) and a basal hooks size of about 8-9 um (bothridial) 

 and 5-6 um (antibothridial). The arrangement of the tentacular 

 hooks, however, correspond between all specimens of N. herdmani 

 and K. pronosoma considered above. 



The only detailed description of the strobila is given by Euzet & 

 Radujkovic ( 1 989) for Kotorella pronosoma. The general morphol- 

 ogy of the proglottids (Fig. 2 in Euzet & Radujkovic, 1989), the 

 central female genital complex, the pre-equatorial irregularly alter- 

 nating cirrus sac and number of testes is corresponding to the type 

 material of N. herdmani (Fig. 9). Thus we conclude that both 

 material belongs to the same species, Kotorella pronosoma (Stossich, 

 1901) Euzet & Radujkovic, 1989. 



DISCUSSION 



With the description of Nybelinia southwelli sp. nov. and the syn- 

 onymy of N. dakari with N. perideraeus and N. herdmani with 

 Kotorella pronosoma, the number of adequately described valid 

 species within the genus Nybelinia is reduced from 44 to 43. 

 However, the genus remains the most species-rich within the order 

 Trypanorhyncha. 



Palm et al. (1997) pointed out that the genus Nybelinia seems to 

 have many species with a cosmopolitan distribution pattern. In the 

 present study, the two synonymies reported further extend the 

 reported range of distribution for both species. Nybelinia perideraeus 

 now can be considered to have a transoceanic distribution. It was 

 originally described from Sri Lanka by Shipley & Hornell (1906), 

 and was re-described as N. dakari from the north-west African coast 

 (Dollfus, 1960) and recorded as N. dakari from the China Sea by 

 Yang et al. (1995). If the specimens labelled N. perideraeus in the 



