394 



DISCOVERY REPORTS 



Tetraphyllidean larva. (Fig. 45.) 



Host: Sperm Whale {Physeter catodon). 

 Locality: South Georgia. 



Only one specimen has been found; it occurred in the same host together with the previously 

 described form. 



The total length of the evaginated cyst is about 9 x 3 mm. The scolex is 1 mm. wide, provided with 

 four discoid suckers, which measure about 420 x 525/x in diameter. 



RELATIONSHIPS BETWEEN THE HOST AND THE PARASITE 



From the material examined it seems that host-specificity does not exist. The only exception is Tetra- 

 bothrius ruudi, which at present has been recorded only in the Fin Whale. This, however, does not 

 mean that this species may not occur in other species of whales, and it is probably a matter of the 

 number of the hosts examined. This appears to be true as far as the present material is concerned. 



Table 2. Infection of hosts with particular species of cestodes 



The Blue Whale has been found to harbour five different species of Cestodes, while in the seven other 

 hosts only one to three different species occurred. Blue Whales formed by far the greater number of 

 the hosts examined (Table 2) and this undoubtedly accounts for the greater variety of worms from 

 this species of whale. Hitherto Diplogonoporus balaenopterae has been found only in the Sei Whale. 

 In the present material this cestode has been found in two other hosts, the Fin Whale and the Blue 

 Whale. The latter appears also to be a new host for Tetrabothrius wilsotii. The Fin Whale is a new host 

 for Priapocephalus grandis and Tetrabothrius affinis. 



Two species of tapeworms may occur together in the same gut, for in Blue Whale, Priapocephalus 

 grandis was found either with Diplogonoporus balaenopterae or with Tetrabothrius affinis, or with 

 T. schaeferi sp.n. Triple infestation has not, however, been noted in any of the hosts examined. 



REFERENCES 



Baer, J. G., 1932. Contribution a I'etude des Cestodes de Cetaces. Rev. Rev. Suisse Zool. xxxix, 3, pp. 195-228. 



Baer, J. G., 1954. Revision taxinomique et etude biologique des Cestodes de la famille des Tetrabothriidae, parasites d'oiseaux de 



haute mer et de Mammiferes marins. Mem. Univ. Neuchatel, I, pp. 1-121. 

 Baylis, H. A., 1926. Some Tetrabothriid Cestodes from Whales of the genus Balaenoptera. Journ. Linn. Soc. London, xxxvi, 



pp. 161-72. 

 Baylis, H. A., 1932. A list of Worms parasitic in Cetacea. Discovery Rep. vi, pp. 395-418. 

 Fuhrmann, O., 1899. Das Genus Prosthecocotyle. Zool. Ang. xxn, pp. 180-3. 



