TENTACULARIID TRYPANORHYNCHS FROM THE NHM 



135 



Fig. 1 Nybelinia aequidentata isolated from Lepturacanthus savala. 

 Scolex. Scale bar=500 |am. 



Fig. 2 N. aequidentata. Homeomorphous metabasal armature. Scale 

 bar=25 |im. 



rose-thorn shaped (L=9.6-12.0, 8.8-12.0; B=7.2-8.8, 7.2-8.8); 

 hsr=7-8. 



The strobila is acraspedote, with about 240 segments, last proglot- 

 tid with rounded proximal end. The first 70 proglottids are very short 

 (10-50 long x 370-530 wide), the next enlarge in size towards 400- 

 500 x 940-1030. The last 20 proglottids are a bit wider than long 

 1050-1200 x 1250-1450. In mature proglottids (Fig. 3), genital 

 atrium ventro-submarginal, in anterior half of the segment; genital 

 pores alternate irregularly. Cirrus sac elongate and slender, 80 x 450 

 in size, directed anteromedially, sac thin-walled; cirrus unarmed and 

 coiled within sac, internal and external seminal vesicle not seen; vas 

 deferens coils medially to mid-line, then posteriorly towards genital 

 complex. Testes of different shape, often ovoid, 70-95 in diameter 

 (55-70 in proglottids 71-160), arranged in a single layer; testes 

 number 80-90 per proglottis, encircle female genital complex and 

 occupy entire medulla except for region of female genital complex 

 and anterior of it. Ovary centrally, follicular, x-shaped with 2 major 

 branches, each 95 x 160. Uterine ducts coiled before they enter the 

 sacciform uterus. Vitelline follicles 25-35 in diameter. 



Remarks. Dollfus (1960) described larvae of N. africana from 

 the body cavity of Galeoides polydactylus, Mullus barbatus, Pagellus 

 sp. Serranus cabrilla, and Trigla sp.. The 3 scoleces measured by 

 Dollfus were variable in size, ranging for example between 750- 

 1100 (SL), 397-540 (pbo) and 19-35 (TW). The BR and SP were 

 between 2.6:1-3.4:1 and 2.1:0.9:1-2.3:1.4:1 respectively and the 

 hook size in the metabasal armature was between 14-17. The 



measurements for the present specimens were smaller and only the 

 SP of the specimen from Carcharhinus leucas directly corresponds 

 to specimen in tube 465 described by Dollfus (1960). However, the 

 similar form and size of the basal and metabasal hooks together 

 with a similar TW lead to the identification proposed. Palm et al. 

 (1997) reported specimens of N. africana from the Mozambique 

 coast which were larger in scolex and hook sizes than the above 

 material. However, the form of the hooks along the tentacle as well 

 as the BR, SP and TW were similar to those described by Dollfus 

 (1960). Thus, it seems that N. africana has a variable scolex size, 

 and, depending on this, a different hook size. However, the charac- 

 teristic hook forms along the tentacle remain the same. Palm & 

 Walter (1999) recognised adults of A 7 , africana from Carcharhinus 

 melanopterus from the Gulf of Suez, Egypt (named as N. 

 perideraeus in Dollfus, 1942) on bases of the scolex size and the 

 tentacular armature, and the present description of adult A', africana 

 supports this synonymy. The strobila characters of the present 

 specimens correspond with that of Dollfus's description in a similar 

 size and shape of the first (10-50 x 370-530 vs 1 1 x 290) and last 

 (1050-1200 x 1250-1450, a bit wider than long vs 1100 x 900, a 

 bit longer than wide) proglottids, the follicular ovary, and similar 

 sized vitellaria (25-35 vs 26-31). The present study records speci- 

 mens from two further carcharhinid shark species and from Mustelus 

 canis from South Africa. They represent new host and locality 

 records, which indicates a circum-African distribution and a low 

 host specificity of adult N. africana, as was earlier proposed for the 

 postlarvae by Palm et al. (1997). 



