Chironomid fauna Piptera: Chironomidae) in the Hosomidani valley, western Chugoku Mountains, Japan

The Hosomidani riparian fbrest, located around the origin of the Ohta River basin, is one of the most nature-rich districts in Japan. We investigated chironomid fauna in the Hosomidani valley as　anindicator taxon to evaluate the species diversity of　&eshwater benthic macroinvertebrates. On 23 August and 2 November, 2005, ironomid lalvae were collected in the main stream of the Hosomidani River, small streamletsflowing Into the main stream and the floodplain marsh along the Hosomidani River,and were reared to adults in the laboratory to identify species. A total of 52 species was collected and of which 17 Were newly recorded in the Ohta River basin Thirty-five species were collected in the main stream and of which 14 were also fblmd in the streamiets. On the other hand, 12 out of 16 species collected inthefloodplain marshes were not found in the main streamand streamiets, Polypedilum (Trliodura) caudocula was only found in the noodplain and this is the second record next tothe descnptlOn Of this species in 1991 ･ These results indicate thaHhe high species diversity of cbironomids in tile Hosomidani valley is supported by the presence of the noodplain,Article信州大学山地水環境教育研究センター研究報告 6: 103-108(2010)departmental bulletin pape

Neoergasilus japonicus（Copepoda: Ergasilidae） parasitic on five species of cyprinid fishes in Okayama Prefecture, Japan

The ergasilid copepod Neoergasilus japonicus was collected from the anal and dorsal fins of the following five species of cyprinids in Okayama city, Okayama Prefecture, Japan, in October of 2016 and 2017: wataka Ischikauia steenackeri, ta−moroko Gnathopogon elongatus elongatus, yari−tanago Tanakia lanceolata, common carp Cyprinus carpio, and gin−buna Carassius sp. These collections represent the first records of N. japonicus from Okayama Prefecture. Wataka is a new host of N. japonicus.ホシザキグリーン財団委託業績 第116

チョウモドキの新宿主と日本における自然分布に関する論議

島根県吉賀町の立河内・蓼野両地区を流れる高津川最上流部の立河内川と無名沢で採集したゴギSalvelinus leucomaenis imbrius 8尾のうち，1尾の頭部背面からエラオ（鰓尾）類チョウ科のチョウモドキArgulus coregoniの成体雄1個体を採集した。これは西日本におけるチョウモドキの初記録である。これまでにゴギからチョウモドキが採集された記録はなく，ゴギは新宿主となる。ゴギは中国地方の一部の河川にのみ生息し，調査河川でゴギ個体群は陸封・分断されており，他のサケ科魚類の放流が過去にないことから，チョウモドキはそこにもともと分布していたと考えられた。これは，チョウモドキは「多分欧州から魚の体表について移入されたものであろう」とする過去の見解を支持しない。An adult male of Argulus coregoni Thorell, 1864 was collected from the skin of a gogi charr Salvelinus leucomaenis imbrius Jordan and McGregor (Salmoniformes: Salmonidae) in the uppermost reaches of the Takatsu River in Yoshiga, Shimane Prefecture, Japan. This finding represents the first record of A. coregoni from western Japan. Salvelinus leucomaenis imbrius is a new host for A. coregoni. This salmonid is endemic to rivers in part of the Chugoku Region, western Japan, and small isolated populations of the fish occurred at the sampling sites. No other salmonids had been stocked there. These facts indicate that A. coregoni is native to the river, which does not support the view put forward in the 1960’s that A. coregoni had been probably introduced from Europe into Japan

Salvelinema salmonicola（Nematoda: Cystidicolidae） parasitic in gogi charr, Salvelinus leucomaenis imbrius（Salmonidae）, in Shimane Prefecture, Japan

The gogi charr, Salvelinus leucomaenis imbrius Jordan and McGregor, 1925, is endemic to western Honshu, Japan, and its parasite fauna remains poorly studied. The cystidicolid nematode Salvelinema salmonicola（Ishii, 1916）was collected from the swimbladder of gogi charr in the Mikazura and Akadani rivers, tributaries of the Takatsu River, Shimane Prefecture, Japan on ８ August 2017. These collections represent a new host record for S. salmonicola.ホシザキグリーン財団委託業績 第120

Genetic relationships of char distributed in the watershed border between three river basins in the eastern Chugoku Region, Japan.

Genetic relationships among a subspecies of white-spotted char, Salvelinus leucomaenis pluvius, distributed in the border area of three river basins in the eastern Chugoku region of Japan (the Sendai River, flowing into the Sea of Japan, and the Yoshii and Chigusa rivers, both flowing into the Seto Inland Sea), were investigated based on mitochondrial DNA cytochrome-b gene sequences. A total of 7 haplotypes were recognized and there were 8 polymorphic sites in a 447 bp fragment. Some haplotypes were shared by fish in two adjacent basins across passes, and some were confined to restricted basins. One haplotype estimated to be the oldest could be connected to ‘Gogi’, S. leucomaenis imbrius. Another haplotype, estimated to have derived in the most recent period, was observed in more than half the samples. There was a significant positive correlation between the geographic and genetic distances. These results suggest that genetic distance was more strongly determined by geographic distance than by river-basin location, and may support the possibility of range expansion of char by taking advantage of geologic events

Darier\u27s Disease with Esophageal Involvement

Letter to the editorNo abstract available</p

日野川水系に分布するイワナ属魚類の亜種，頭部斑紋型，遺伝子型の組成について

鳥取県日野川水系におけるイワナ属魚類について，ゴギとニッコウイワナ，頭部斑紋型，遺伝子型の組成を調べた。計19の支流から38個体のサンプルが採集され，支流はその発する山塊ごとにグループ化された。ニッコウイワナは水系東部の大山・二子・花見山塊から発する支流に分布したが西部5山塊からの支流には分布せず，対照的にゴギは水系西部の鬼林・道後・三国・船通・鷹入山塊に分布したが東部3山塊には分布しなかった。斑紋型では東部3山塊ではＣ・Ｅ・Ｆ・Ｇ・Ｈは記録されたがＡ・Ｂ・Ｄ型は記録されなかった。一方，西部5山塊ではすべての型が記録された。遺伝子型では6および9つのハプロタイプがそれぞれニッコウイワナおよびゴギ特異的であり，1タイプのみ共通であった。デンドログラムではニッコウイワナおよびゴギそれぞれ5および6つのハプロタイプで構成される亜種特異的なクレードが見られたが，もう一つのクレードは両亜種で形成された。これらの結果は，日野川における両亜種の混棲，ゴギの複数起源性，地形変動等による分布拡大，さらに斑紋の易変異性を示唆する。Composition of 2 subspecies of white-spotted charr, Salvelinus leucomaenis imbrius (“Gogi”) and S. l. pluvius (“Nikko-iwana”), head spot types and genetic types were investigated for the Hino River, Tottori Prefecture, Japan. A total of 38 charr samples was collected from the 19 branches. All the branches were categorized into 8 groups based on the mountain mass from which the branch originates. Nikko-iwana was distributed in the Daisen, Futago and Hanami mountain masses in the eastern part of the basin and was not distributed in the other 5 mountain masses in the western part. In contrast, Gogi was distributed in the western Onibayashi, Dogo, Mikuni, Senzu and Takairi mountain masses and was not distributed in the 3 eastern mountain masses. For head spot types, C, E, F, G and H were distributed in the 3 eastern masses whereas A, B and D were not recorded from these masses. On the other hand, all the types were distributed in the 5 western masses. For genetic types, 6 and 9 haplotypes were Nikko-iwana- and Gogi-specific, respectively. Only a haplotype comprised both subspecies. In the dendrogram, 5 haplotypes constructed an exclusive clade of Nikko-iwana whereas 6 haplotypes constructed an exclusive clade of Gogi. However, the remaining clade was constructed by both subspecies. These results suggest the co-existence of both subspecies in the Hino River, multiple origins of Gogi, movements of charr by topographic events and plasticity of the head spots

海産ユスリカ種の形態学的系統樹と遺伝学的系統樹の関係

海産4属，Clunio，Semiocladius，TelmatogetonおよびThalassosmittiaと陸生のSmittia，淡水性のCricotopus属のエリユスリカ亜科と近縁亜科の形態学的系統樹と遺伝学的系統樹の関係を調べた。遺伝学的系統樹では3系統，すなわちSmittia，SemiocladiusとClunioを含む他の4属に分かれた。さらに，TelmatogetonとThalassosmittiaは別亜科にも拘わらず小さなクラスターを形成した。形態学的系統樹ではSemiocladiusとClunioは小さなクラスターを形成したが，TelmatogetonとThlassosmittiaはこれらだけではクラスターを形成しなかった。Cricotopusは最後に大きなクラスターに加わった。これらの結果は，Clunio，TelmatogetonとThalassosmittiaは淡水種の祖先から派生したこと，そして形態学的形質の中にいくらかの平行進化が存在することを示唆する。Relationships between morphological and genetic trees of 4 marine orthoclad and related genera, Clunio, Semiocladius, Telmatogeton and Thalassosmittia, of the dipteran family Chironomidae as well as a terrestrial genus Smittia and a freshwater genus Cricotopus were examined. In the genetic tree, there were 3 lineages; Smittia, Semiocladius and other 4 genera, comprising Cricotopus. Telmatogeton and Thalassosmittia formed an intimate clade in spite of their different affiliations to the subfamily. Semiocladius and Clunio made a small clade in the morphological tree, whereas Telmatogeton and Thlassosmittia did not form a clade by themselves. Cricotopus participated in the largest cluster. These results suggest that Clunio, Telmatogeton and Thalassosmittia have derived from a freshwater ancestor and there be some morphological parallelisms

太田川水系におけるナガレトビケラ科幼虫各種の分布様式の違いについて

太田川水系の全体を網羅するいろいろな幼虫群集を調べることによって，ナガレトビケラ科幼虫の分布様式を比較した。合計15種が採集され，どの環境パラメータについても，分布範囲と平均値は種間で著しく異なった。Rhyacophila bilobata，R. shikotsuensisおよびR. sp. RFは，源流からの距離，川幅および流域面積について，狭い範囲と小さな標準偏差を示した。各パラメータを標準化し，8つのパラメータについての分布平均に基づいてクラスター分析を行った。すべて原始的な種であるR. bilobata，R. clemensとR. sp. RKからなるクラスターは，高標高，急な川床勾配，小規模，貧栄養で低温の水域に適応してきたと推定された。共に派生的な種であるR. nigrocephalaとR.yamanakensisからなるクラスターは，低標高，緩い川床勾配，大規模，富栄養で高温の水域に適応してきたと推定された。さらに，Nigrocephalaグループの一員であるR. nigrocephalaがR.nigrocephalaのクラスターを形成したのに対し，同グループのR. kawamuraeはApsilochoremasutshanumのクラスターに加わった。これらの結果は，祖先種の本来の生息地は源流域であること，分布制限要因は種間で異なること，さらに近縁種間で何らかの棲み分けがあることを示唆する。The distribution pattern was compared among the caddisfly larvae of the family Rhyacophilidae by examining the various larval communities covering a total basin of the Ohta River, Japan. A total of 15 species were collected, among which the distribution range and the mean was remarkably different for any environmental parameter. Rhyacophila bilobata, R. shikotsuensis and R. sp. RF showed a narrow range and small standard deviation for distance from riverhead, river width and valley area. Each parameter was standardized, and cluster analysis was performed on the basis of the means of 8 parameters for distribution of each species. A cluster, involving R. bilobata, R. clemens and R. sp. RK, all primitive, was estimated to have adapted to high altitude, steep riverbed slope, small-scale, oligotrophic and low-temperature waters. Another cluster, involving R. nigrocephala and R. yamanakensis, both derivative, was estimated to have adapted to low altitude, loose slope, large-scale, eutrophic and high-temperature waters. Besides, R. kawamurae, a species of Nigrocephala group, participated in an Apsilochorema sutshanum-cluster whereas R. nigrocephala, another species of the same group, constructed a R. nigrocephala-cluster. These suggest that the original habitat of the ancestral species be headwaters, that strongly restricting factors be different among species and that there be some habitat-partitionings among the sibling species

Field experiments on chironomid phototaxis at the shore of Lake Kojima, Japan

Phototaxis in response to a variety of lamps, including white and colored fluorescent and LED lamps, was compared by species and sex among the chironomids, from Lake Kojima, Okayama Prefecture, Japan. Males were usually much more attracted to lights than were females. Pantanal white attracted the highest number of species among six white lamps. Among five colored lamps, Blue attracted the highest number and Black the lowest number. Among 5 LED lamps, Blue again attracted the highest number and Amber the lowest number. In terms of the number of individuals attracted, Pantanal white was the highest among white lamps for the seven major species. Green and Blue were the highest for the six and seven major species, respectively, and Yellow and Red did not attract the highest number of individuals of any species among colored lamps. Green LED was the highest among LEDs for the seven major species while Amber and Red LEDs were not the highest for any species