TENTACULARIID TRYPANORHYNCHS FROM THE NHM 



143 



different scolex form (see above), larger TW and TSW and the 

 tentacular hooks are larger. In contrast, the morphological measure- 

 ments SL, TL, TW, TSW and the small size and form of the hooks 

 are similar to N. oodes (SL=920, TL=400-500, TW=24-27, 

 TSW=40^8, B=9.3-10.6) as described by Dollfus (1960). Exami- 

 nation of the type material revealed a slightly heteromorphous 

 tentacular armature for N. oodes. This neither corresponds to the 

 original description (see Dollfus, 1960, Figs 36-37) nor to the 

 present specimens. Thus, the present postlarvae should not be 

 assigned to Nybelinia oodes and might represent a new Nybelinia 

 species. This needs to be decided after re-description of the Nybelinia 

 type material deposited at the MNHN Paris. 



Heteronybelinia gen. nov. 



Trypanorhynchs with the characters of the Tentaculariidae Poche, 

 1926. Scolex compact, 4 triangular bothridia, with hook-like 

 microtriches along the bothridial borders and filamentous 

 microtriches on the rest of the bothridia and the scolex. 4 tentacles 

 emerging from bulbs, retractor muscle originates at base of bulbs. 4 

 proboscis of variable length and width, armed with hooks; metabasal 

 tentacular armature homeoacanthous with heteromorphous hooks 

 on different tentacle surfaces. Basal hooks heteromorphous, charac- 

 teristic basal armature absent or present. Cirrus unarmed, cirrus sac 

 alternates irregularly. 



TYPE SPECIES. Heteronybelinia estigmena (Dollfus, 1960). 



Other species. H. alloiotica (Dollfus, 1960), H. cadenati (Doll- 

 fus, 1960), H. elongata (Shah & Bilquees, 1979), H. eureia (Dollfus, 

 1960), H. heteromorphi sp. nov., H. karachii (Khurshid & Bilqees, 

 1988), H, minima sp. nov., H. nipponica (Yamaguti, 1952), H. 

 perideraeus (Shipley & Hornell, 1906), H. punctatissima (Dollfus, 

 1960), H. robusta (Linton, 1890), H. rougetcampanae (Dollfus, 

 1960), H. senegalensis (Dollfus, 1960), H. yamagutii (Dollfus, 

 1960), all formerly belonging to the genus Nybelinia Poche, 1926. 



Comment. This new genus comprises subgroup II in Palm et al. 

 (1997). 



10. Heteronybelinia elongata (Shah & Bilqees, 1979) 

 comb. nov. (Figs 19-25) 



Material examined. Types BMNH 1989.5. 18.5, Shah & Bilqees 

 leg., 1979, 2 postlarvae from Pellona elongata, Pakistan; BMNH 

 1980.6.23.13, A. Roy leg., 1 postlarva from the gonads of 

 Lepturacanthus savala, Hooghly estuary, India. Other material not 

 measured: BMNH 1992.7.1.193-196, A. Roy leg., postlarva from 

 Lepturacanthus savala, Sugar Island, Bay of Bengal. 



Description. The scolex morphology of the type material of H. 

 elongata (Shah & Bilqees, 1979) from Pellona elongata, together 

 with the scoleces and armature of specimens from Lepturacanthus 

 savala, are given in Figs 19-25. The type material is re-described as 

 follows (Fig. 19): The scolex is about 2 mm large, but is variable in 

 size, SL=2173, 2362 (a third specimen on the same slide: 1740); 

 SW=1000, 1021; pbo=982, 964; pv=1021, 1021; pb=536, 548; 

 ppb= 227, 252; app=605, 624; vel=302, 300; BL=514 (490-536), 

 525 (510-548); BW=130 (125-135), 128 (112-144.8); BR=3.9:1, 

 4.1:1; SP= 1.8:1.9:1. The tentacles are long and slender with aTW 

 metabasal =15.2-17.6; TW basal= 17.6-20.8, diminishing slightly 

 towards the metabasal part of the tentacle. A basal tentacular 

 swelling is absent. Prebulbar organs were absent, muscular rings 

 around the basal part of the tentacle sheaths were visible in some 



specimens (see also Fig. 22). Tentacle sheaths straight; retractor 

 muscles originate at the basal part of the bulbs. 



The tentacular armature is homeoacanthous, heteromorphous, 

 and a characteristic basal armature is absent (see Figs 23-24). The 

 form of the hooks is rose-thorn shaped. The hook size in the 

 metabasal region (see Fig. 25) ranged between L= 1 1 .2-12.8: B=9.2- 

 11.2, 11.2-12.8 (bothridial) and L=9.2-11.2, 8.8-11.2; B=5.6-7.2, 

 7.2-9.2 (antibothridial), and the hook size in the basal region of the 

 tentacle was between L=9. 2-11.2; B=9.2-11.2 (bothridial) and 

 L=5.6-7.2; B=4-5.6, 5.6-7.2 (antibothridial); the hook size in- 

 creases only on the antibothridial tentacle surface; hsr=6-7. 



Postlarvae from Lepturacanthus savala (Fig. 20): Measurements: 

 SL=1360; SW=642; pbo=662; pv=605; pb=397; ppb=61; app=257; 

 vel=233; BL=387 (377-397), BW=91 (89-94); BR=4.2:1; SP= 

 1.7:1.5:1. The tentacles are long and slender with a TW metabasal 

 =20.8-24; TW basal= 24-27.2. A basal tentacular swelling is ab- 

 sent. Prebulbar organs are absent and muscular rings around the 

 basal part of the tentacle sheaths are present; TSW= 32.8-36, 

 straight; retractor muscles originate at the basal part of the bulbs. 



The hook size in the metabasal armature ranged between L=9.6- 

 11.2; B=9.2-l 1.2 (bothridial) and L=8.0-9.2; B=5.6-7.2 

 (antibothridial), and the hook size in the basal part of the tentacle 

 was between L=7.2-9.2; B=7.2-9.6 (bothridial) and L=4-5.6; B= 

 5.6-7.2 (antibothridial); The hook size increases mainly on the 

 antibothridial tentacle surface towards the metabasal part of the 

 tentacle; hsr=6-7. 



Scoleces, muscular ring and the tentacular armature of specimens 

 BMNH 1992.7.1.193-196 are shown in Figs 21-25. 



Remarks. The type material of N. elongata from Pellona elongata 

 is re-described, as well as additional material of the same species 

 collected from Lepturacanthus savala. Though the material differs 

 in absolute morphometrical values, BR, SP and the tentacular 

 armature are very similar. Recently, Palm & Walter (1999) exam- 

 ined the type material of N. perideraeus from the Natural History 

 Museum Vienna and re-described the species as having a 

 homeoacanthous, heteromorphous tentacular armature. The authors 

 considered N. dakari to be synonymous with N. perideraeus, char- 

 acterised by tentacular hooks of similar size in the basal and metabasal 

 part of the tentacle. The present material of N. elongata also has very 

 similar scolex measurements as well as similar tentacular hooks to 

 those of N. perideraeus. However, the hook size increases on the 

 antibothridial tentacle surface towards the metabasal part of the 

 tentacle. Thus, until further material becomes available, both spe- 

 cies are considered valid. The position of N. elongata changes from 

 subgoup IAb to II Aa in Palm et al. (1997). 



N. elongata appears to have a high degree of scolex variability, 

 e.g. the SL ranges between 1739 and 2362 in 3 different specimens 

 on the same slide. As well as similarities between N. elongata and N. 

 perideraeus, a close relationship can be seen to other species from 

 subgroup IIAa, all having a similar armature with similar sized 

 tentacular hooks. It is recommended that the type material of species 

 in subgroup IIAa described by Dollfus (1960) be compared with N. 

 perideraeus and N. elongata to clarify the species identity within 

 this subgroup (also see below). 



11. Heteronybelinia estigmena (Dollfus, 1960) comb. nov. 



(Figs 26-28) 



Material examined. BMNH 1976.11.5.42^3, R. van der Elst 

 leg., 1 adult from the gut of Carcharhinus limbatus, South Africa; 

 BMNH 1985.11.8.63-64,. R. van der Elst leg; 11.05.1984, 1 adult 

 from Carcharhinus leucas, Richards Bay, South Africa; BMNH 



