TENTACULARIID TRYPANORHYNCHS FROM THE NHM 



141 



Fig. 14 Nybelinia schmidti sp. nov. Scolex from Isurus glaucus. Scale 

 bar=100|im. 



Fig. 15 N. schmidti sp. nov. Homeomorphous basal and metabasal 

 armature. Scale bar=10 urn. 



and a distinctive basal armature is present (Fig. 17). The basal 

 armature consists of about 1 1 rows with compact rose-thorn-shaped 

 hooks, increasing in size (row 1-5: L=3. 5-5.6, B=3.5-4.9, and row 

 6-11: L=7-9.8, B=5.6-8.4). From rows 12-14, the hook form 

 changes to long, spiniform metabasal hooks (L=22-26) with a small 

 base (B=7.7-10.5); hsr basal=6-7, hsr metabasal=4-5. 



No complete strobila is present. The first acraspedote proglottids 

 are wider than long (330 x 50) and slightly increasing in size (490 x 

 205). Other internal structures were not seen. 



REMARKS. Palm & Walter (1999) considered Nybelinia (Tentacul- 

 aria) scoliodoni (Vijayalakshmi, Vijayalakshmi & Gangadharam, 

 1996) as a species of uncertain status due to an uncomplete original 

 description and a strong similarity to Nybelinia indica Chandra. 

 1986. However, the present specimen confirms the validity of 

 Tentacularia scoliodoni, and assigns the species to the genus 

 Nybelinia Poche, 1926. Though the scolex measurements of the 

 present specimen are smaller and the scolex and bulb ratios show 

 differences to those given in the original description, the tentacular 

 armature corresponds in detail with N. scoliodoni. The drastic 

 change in form from rose-thorn shaped basal to spiniform metabasal 

 hooks, with a size between L=8-l 1 in the basal and L=30, B=3 in the 

 metabasal armature as given by Vijayalakshmi et al. (1996), is 

 unique within the genus. As with the scolex size, the hooks of the 

 present specimen are slightly smaller than those of the original 

 description. However, Vijayalakshmi etal. (1996, figure 8) demon- 

 strated minute hooks on the basal part of the tentacle, similar to those 

 in rows 1-5 of the present specimen, and also indicated the charac- 

 teristic change in TW along the tentacles (figure 7). The known 

 range of distribution is extended to South Africa, and Carcharhinus 



limbatus is a new host for N. scoliodoni. Under the co-type material 

 of Nybelinia perideraeus (Shipley & Hornell. 1906), slide No. 12f, 

 an adult N. scoliodoni with an uncomplete strobila was found. The 

 scolex size and tentacular armature corresponds to the material 

 deposited at the BMNH. Thus, Glyphis gangeticus represents a new 

 host for N. scoliodoni, and this finding supports its occurrence in 

 Indian Ocean waters. 



N. scoliodoni has similarities with N. indica Chandra, 1986, which 

 was also described from the Indian Ocean. N. indica differs due to its 

 larger size, a large ppb, a larger TW in the basal part of the tentacle and 

 a more gradual change in hook form along the tentacles (Chandra, 

 1986). In contrast to this, the form of the hooks as well as their size 

 show similarities to both N. scoliodoni and the present specimen. The 

 real identity ofN. indica and a possible synonymy with N. scoliodoni 

 cannot be decided until a re -examination of the type material is 

 undertaken. Therefore, both species remain valid, and on the basis of 

 the above described characters, the present specimen is identified as N. 

 scoliodoni. The present specimen was obtained from a carcharhinid 

 shark from South Africa, which further extends the distribution of the 

 species from the Indian to the South African coast. 



Palm (1997b) found similar small Nybelinia specimens (SL=640, 

 SP=3.6:2:1) with a similar tentacular armature (L=5-24, rose-thorn 

 shaped basal and spiniform metabasal hooks (Fig. 18; figure 17 in 

 Palm, 1992) in Pseudupenaeus maculatus from the North-East 

 Brazilian coast and described the specimens as N. indica with a 

 homeomorphous metabasal armature. The drawing of the tentacular 

 armature of one of the specimens as given in Palm (1992) shows 

 similar hooks as demonstrated for the present specimens. However, 

 its affinities with N. indica or N. scoliodoni cannot be decided at 

 present (see above). 



