En face view ofMansonella (Mansonella) akitensis(Uni, 1983) by scanning electron microscopy

Abstract

The architecture of the cephalic extremity is an important key to differenciate the subgenera in the genus Mansonella (Anderson and Bain, 1976 ;Chabaud and Bain, 1976 ;Eberhard and Orihel, 1984 ;Orihel and Eberhard, 1982).M. akitensis from the Japanese black bear was examined by SEM for its en face view of the head on one female adult recently collected from the perirenal adipose tissue of a black bear of the type locality, Akita, Japan. The microfilariae of this species were also found in the blood of the bear. SEM of the head revealed four pairs of submedian papillae, one pair of conspicuous amphids and a small slit-like mouth at the center (fig. 1) . The amphidial pores were closely situated laterally at the center. The arrangement of the labial papillae was expanded dorsoventrally. The configuration of the cephalic extremity is shown on the basis of the scanning electron micrographs in figure 2.However, the interlateral papillae originally described by Price (1962) in M. interstitium and M. llewellyni were not found in the specimen of M. akitensis.The present finding of en face view of the head by SEM was in accordance with the definition of the subgenus Mansonella, confirming the taxonomical position of M. akitensis in the genus Mansonella (Eberhard and Orihel, 1984).