open access

https://hdl.handle.net/2115/68413

Polycelis akkeshi, a New Freshwater Planarian, from. Hokkaido

英語

1963-02

Akkeshi Marine Biological Station

Publications from the Akkeshi Marine Biological Station

12

2-18

In 1952, during an investigation of freshwater planarians in Hokkaidö conducted by the senior author, A. Ichikawa, several specimens of white planarian were collected in the brooklet running through the compound adjoining the Akkeshi Marine Biological Station attached to the Faculty of Science of Hokkaido University, Akkeshi-chö, in eastern Hokkaidö. An examination of the material revealed that the worms belonged to the genus Polycelis. But the presence of an extraordinarily thick muscle zone surrounding the male antrum differentiates it from Polycelis sapporo (Ijima et Kaburaki), a most common unpigmented Polycelis species in Hokkaidö. Unfortunately, in this material, none of the animals was fully mature (cf. Ichikawa 1954: Abstract of a lecture delivered before the 24th Annual Meeting of the Zoological Society of Japan held in Kyoto, on Nov. 1st-2nd, 1953). Recently, the writers made several visits to the locality of those planarian specimens and a good number of planarians could be found in the hill streams near the Station. In laboratory cultures, the writers succeeded in obtaining many sexually mature specimens. In the summer of 1962 the junior author also took numerous sexually mature specimens of this planarian species in brooks and booklets in the vicinity of Mt. Apoi, Hidaka, in southern Hokkaidö and in the spring at Kaminayoro, Kamikawa, northern Hokkaid6. After having re-examined a sufficient number of the worms the writers came to the conclusion that this freshwater planarian is a new species in the Japanese fauna. The taxonomic description of this form is here reported, together with some additional data. The worms were killed by Sugino's method (pour 2gä hydrochloric acid over living worm) and were fixed in Bouin's fluid. Serial sections were stained with haematoxylin and eosin. Some of them which were killed by Sugino's method were fixed in Nozawa's fluid (95 go ethyl-alcohol 45 cc+ formalin 10 cc+ acetic acid glacial 2 cc), and were stained with borax-carmin as a whole mount. For the tracing of the digestive system , the following method was used: feed a bit of chicken spieen stained with a fluid of Chinese ink-stick to the hungry worms. After this treatment ,. the worms which were killed by Sugino's method were fixed in Nozawa's fluid, and were prepared as whole mounts without any staining (cf. Ichikawa & Kawakatsu 1961, pp. 14-48).

紀要論文

Version of Record

0439-349X

AA00795172