New molecular sequences for two genera of marine planarians facilitate determination of their position in the phylogenetic tree, with new records for two species (Platyhelminthes, Tricladida, Maricola)

For the first time, molecular sequences of the 18S ribosomal DNA were generated for representatives of the genera Obrimoposthia Sluys & Ball, 1989 and Paucumara Sluys, 1989 of the suborder of the marine triclads, or Maricola, by analyzing the species Obrimoposthia wandeli (Hallez, 1906) and Paucumara trigonocephala (Ijima & Kaburaki, 1916). On the basis of this molecular data the phylogenetic position of these two genera in the phylogenetic tree of the Maricola was determined and compared with their position in the phylogeny based on the analysis of anatomical features. New records for these two species are documented and their taxonomic status is determined on the basis of histological studies

Polycelis akkeshi, a New Freshwater Planarian, from. Hokkaido

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)

Additional notes on freshwater planarians from Lake Tahoe in the Sierra Nevada Mountains in North America

Several years ago I described two species of freshwater planarians that occur at the bottom of Lake Tahoe in the Sierra Nevada Mountains in California and Nevada, U. S. A. (KAWAKATSU 1968). These lake-dwelling species are : Phagocata tahoena KAWAKAT SU, 1968 (olim Phagocata nivea tahoena), and Dendrocoelopsis hymanae KAWAKATSU1,9 68. Only preserved specimens (fixed in 99 % isopropyl alcohol) were studied. When I studied the species in the spring of 1965, the material of Phagocata tahoena was sufficient for a histological study, but that of Dendrocoelopsis hymanae was only two dried specimens, one sexually mature and the other immature. They were softened in a fluid of glycelin-ethyl alcohol but did not permit a thorough histological analysis of the anatomy. In September of 1967 and again in July of 1968, Dr. Roman KENK, of the Museum of Natural History, Smithsonian Institution. visited the Lake (near Al Tahoe, El Drado County, California, Emerald Bay of Lake Tahoe, El Drado County, California, and off Pope Beach, El Drado County, California) and collected a sufficient number of animals of Phagocata tahoena. The material of Dendrocoelopsis hymanae was not collected during his trips. KENK (1970) described some additional morphological, histological and anatomical features of Phagocata tahoena based upon his new material. He also corrected the taxonomic position of Phagocata nivea tahoena as Phagocata tahoena. I fully agree with Dr. KENK\u27S opinion. Some ecological notes on the habitats of the Lake Tahoe planarians are found in the following literatures: KAWAKATS(U19 65. 1968) and KENK(1970). Films including many photomicrographs of the slides of the Lake Tahoe planarians taken by myself during the spring of 1965 are deposited in my laboratory. The purpose of this paper is a publication of some of these photomicrographs. These may be useful for the future taxonomic study of the Lake Tahoe planarians. I have also added two photographs showing the prospect of Lake Tahoe taken by Mr. Ted C. FRANTZ