抄録
Termites of most isopteran families and wood-feeding cockroaches of the genus Cryptocercus usually harbor more than one symbiotic flagellate species in their hindgut. To evaluate the similarity of their symbiont faunae, data on symbiont composition at a generic level were examined by cluster analysis and type III quantification method. In both analyses, the symbiont composition recorded from host insects belonging to the same families or monophyletic family groups tended to be similar. This tendency was particularly remarkable in the clade Kalotermitidae and the clade Rhinotermitidae plus Serritermitidae. Two basal host groups, the Cryptocercidae and the Mastotermitidae, exhibited very different symbiont compositions. These findings suggested that the symbiont faunae mainly reflect the host's phylogenetic relationships. Within the Rhinotermitid hosts, the genus Reticulitermes showed a unique symbiont fauna although it is not a basal taxon in the Rhinotermitidae. Horizontal transfers of symbiotic protists might explain such anomalistic fauna.
