Taenia Linnaeus, 1758

Sasaki, Mizuki, Anders, Jason Lee & Nakao, Minoru, 2021, Cestode fauna of murid and cricetid rodents in Hokkaido, Japan, with assignment of DNA barcodes, Species Diversity 26, pp. 255-272 : 266

Genus Taenia Linnaeus, 1758 8. Taenia crassiceps ( Zeder, 1800)

The larval cysticerci of Taenia crassiceps were found from the subcutaneous tissue of My. rufocanus in Asahikawa ( Fig. 9A ). This is the first record from Hokkaido. More than 50 proliferating cysticerci were recovered from one vole. The morphometric feature of the cysticercus is as follows: Whole body 1.0– 2.3 mm in maximum diameter. Scolex armed with 34 hooks. Large hooks 0.173 –0.175 long (n=10), 17 in number. Small hooks 0.133 –0.136 long (n=10), 17 in number. The cox1 sequence of the cysticercus (no. 19AK309) showed 99.8％ similarity (939 out of 941 nucleotides identical) to that of T. crassiceps from North America (database accession no. AF216699 ) ( Le et al. 2000).

This species is widely distributed in the northern hemisphere ( Deplazes et al. 2019). The larval cysticerci were already found from Ap. speciosus and Mi. montebelli in Honshu ( Sato and Kamiya 1989; Uchida et al. 1990, 2001; Ihama et al. 2000). Canid carnivores serve as the definitive hosts ( Freeman 1962), and the cysticerci multiply in the subcutaneous tissue and body cavity of wide-ranging mammalian intermediate hosts including humans ( Delvalle 1989; Miyaji et al. 1990; Deplazes et al. 2019). In Hokkaido, the main definitive host is still unclear.

Figures

Fig. 9. Larvae of the family Taeniidae. A, The proliferated cysticerci of Taenia crassiceps in the subcutaneous tissue of Myodes rufocanus; B, the strobilocercus of Hydatigera taeniaeformis from the liver of Rattus norvegicus; C, the disseminated alveolar hydatid of Echinococcus multilocularis in peritoneal organs of My. rufocanus. Scale bars: 20mm.