Examination of the morphological and genetic features of spined loach (Cobitis sp.) collected from the Oyodo River system, southern Kyushu Island, Japan, indicated that they represented a new taxon. The specimens were clearly distinguished from other known Japanese Cobitis species by their mitochondrial DNA sequences. In addition, the shape of the adult male lamina circularis differed to those of the C. sp. ‘yamato’ complex and C. biwae.

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Two voucher specimens of the spined loach, Cobitis matsubarae Okada and Ikeda, 1939, collected from the Shonai River, a branch river of the Oyodo River system, southern Kyushu, Japan, represent the first reliable record of that species from the Oyodo River system. Morphological features of the male lamina circularis, prepelvic myotome number, maxillary barbel length, snout length, body pigmentation patterns, and genetic characteristics of mtDNA cytb sequences were in close agreement with characters those of C. matsubarae. Together with C. sakahoko, C. matsubarae, is considered to be distributed naturally in the Oyodo River system.

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In order to clarify the distribution pattern of three Japanese spined loach species’ complexes in the genus Cobitis (‘yamato’, biwae, and striata complexes) in north-eastern Kyushu Island, 106 specimens obtained from 19 drainage systems were morphologically and genetically examined. Although that region has been previously considered occupied only by the ‘yamato’ complex, some populations of the biwae and striata complexes were confirmed, the distribution patterns being explained by the paleo-Setouchi drainage pattern during the most recent Pleistcene glacial periods. Distinctive populations within the middle race of striata complex included 2 new local forms in Fukuoka Prefecture (the Setouchi form, Hakata form and Onga form).

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Morphological and genetical analyses revealed a spined loach population from Tango District, Kyoto Prefecture, to be an allotetraploid form of Cobitis striata. The former had distinctive differences in body coloration and mitochondrial DNA sequences from another allotetraploid form of Cobitis striata, found inLake Biwa, and is tentatively termed the ‘Tango tetraploid form’ of C. striata.

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The distribution range of the Japanese spined loach Cobitis biwae is in the middle stretches of rivers in most of Honshu and Shikoku Islands. In Kyushu Island, its close relative, the yamato complex sensu Saitoh et al.(2000), is distributed, but C. biwae is thought to be absent there. Comparison of the morphological characters and erythrocytic size revealed that the specimens of Cobitis collected from the Oita River system in Kyushu Island are the tetraploid form of C. biwae. Subsequent mitochondrial DNA analyses also supported this finding. Taking the connection pattern of drainages during glacial periods into consideration, it is suggested that C. biwae from the Oita R. s. is native.

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九州北部の主要な一級河川の水文水質および水辺の国勢調査データに，九州大学が保有する魚類相データを加えて，水質と純淡水魚類との関係を解析した。流水性魚類の種数はBODと負に相関した一方，止水性魚類の種数は相関を示さなかった。Receiver operating characteristic curve解析を行ったところ，幾つかの魚種の出現／非出現がBODに左右されていた。2001-2010年の期間は1991-2000年よりもBODが低く，魚類の出現種数が多かったことから，近年の水質改善が魚類の多様性回復に貢献したと評価される。

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　多自然川づくりなどための魚類調査の労力を軽減するため，生物から水中に放出されるDNA（環境DNA）分析が注目されているが，断面代表値を得るための採水方法や流下距離は不明確である．本研究では，まず河川2断面の横断方向３点，水深方向2点の計6点で採水し，メタバーコーディング解析を行うことで，横断面での環境DNAの分布と断面代表試料の採水方法を検討した．次に10断面で採水してqMiFish法で定量分析し，上流で検出され，下流では検出されない魚種の事例を収集し，環境DNAの減少速度係数を求め，流下距離を推定した．その結果，横断方向3点で表層水を採水することでほぼ断面を代表する試料が得られること，環境DNA減少速度係数は3.55[hr^-1]であり，流下距離は環境DNA濃度と流速に応じて0.1～3.5kmに変化することを示した．

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The aim of this study is to evaluate in-stream restoration method that made from timber log and rock in Kamisaigo river. We conducted fish sampling survey from 2011 (before restoration) through 2012(after restoration). We also conducted physical environment survey and habitat classification survey to assess the environmental condition change of the stream.

From the result, average fish richness was significantly raised from 2011 to 2012. Also habitat variation and physical environment were diversified by the restoration method (log structure). From an economic point, log structure could be installed without heavy equipment that log structure can be constructed cheaply and conveniently by human power.

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 Development of methods to predict the changes in fish biomass due to the changes in flow field is very important to evaluate the impact of river management on the ecosystem. In this study, we developed a method to predict fish biomass in all parts of river's main stream. The weight of each fish species was calculated by visual observation and sampling and then re-classified into four categories: ‘amphidromous-necton’, ‘amphidromous-benthos’, ‘freshwater-necton’, and ‘freshwater-benthos’ to set objective variables of generalized linear models (GLMs). The results of GLMs analysis showed that the predicting models of biomass can be constructed for all four categories by using hydraulic characteristics. The method developed in this study can be applied in river management to evaluate the relationships between environmental changes and biomass of the entire basin.

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A large number of studies have been made on longitudinal changes of fish fauna, however, the relationship with the engineered viewpoint is little known. The purpose of this paper is to investigate relationship between longitudinal changes of fish fauna and segment classification defined from the viewpoint of flood control.
We focused on 15 rivers in Kyushu and run TWINSPAN analysis to divide the fish fauna longitudinally and compared segment classification.
The result of analysis showed that segment classification is largely corresponded with longitudinal changes of fish fauna and the values of longitudinal gradient which is the boundary of longitudinal fish fauna classification are 1/2000, 1/1000 and 1/100.

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1)西日本産シマドジョウ類の12地方種族の形態的生態的差異について述べた.
2)9水系の11地方種族間に17組以上の雜種をつくり, その不姙現象について記載した.
3)池田氏の分類に基く種間雜種及び亜種聞雜種は完全に近い不姙となる.又同種内雜種にも同様な不姙現象を呈するものがある.
4)生理的隔離の有無を基準にして, 本邦産シマドジョウ類は池田氏の分類とは違つた數種に分けることが出來る.

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The aim of this study is to evaluate in-stream restoration method that made of stones in Kamisaigo river. We conducted fish sampling survey from 2014 (before restoration) through 2015(after restoration). We also conducted physical environment survey and habitat classification survey to assess the environmental condition change of the stream. Following results are obtained. In terms of the number of species of fish and the number of individuals that emerged, the effect of introducing the environmental method was not recognized. However, it was confirmed that the number of individuals increased after restoration such as eels, which utilize gaps between gravels, and it was suggested that it may have certain effects. When introducing the environmental stone method into the sand river, it was confirmed that the sediment around the riprap was moved, the riprap gradually settled and buried in about a year.

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The system for supporting nature-oriented river work was developed for administrative agencies to perceive the distribution of fish species and necessary considerations to conserve or to recreate its habitat in advance to construction works such as river improvements. Distribution maps for 40 fish species, which include primary freshwater fish inhabit the Chikugo and the Onga River systems together with ayu (Plecoglossus altivelis) and Japanese eel (Anguilla japonica), were developed by constructing distribution models for each species by logistic regression analysis based on known habitats and environmental variables such as landscape and land use. Furthermore, options of environmental consideration in construction works for the habitat conservations or recreations were organized in charts. Those outcomes are applied to the Web-based GIS system based on the GSI maps (issued by the Geospatial Information Authority of Japan) which could be browsed with simple operation.

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Genuine freshwater fish faunas of 32 rivers in Fukuoka Prefecture, northern Kyushu, Japan, were surveyed between 1998 and 2005, in order to clarify their geographical distribution patterns. A total of 39 fish species/subspecies (10 families) were recorded in the field survey and from existing literature, a cluster analysis separating them into the Chikuzen-Chikugo and Chikuho-Buzen groups. The former was considered to include fauna influenced by mainland China and the Korean Peninsula, the latter being similar to the freshwater fish fauna of rivers flowing to the Seto Inland Sea. The freshwater fish species in Fukuoka were roughly divided into those that occurred in rivers regardless of river length and those that tended to be present in rivers exceeding a certain length. The genuine freshwater fish fauna in Fukuoka is considered to have evolved through geographical isolation and the restriction of river length.

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Mating behavior and early development of Cobitis sp. (BIWAE type D, TosaShima-dojo) were observed in the laboratory by inducing spawning of females with human chorionic gonadotropin (HCG). Subsequently, laboratory bred individuals were compared with spawned eggs and larvae obtained from the field. Mature adults, naturally spawned eggs, and larvae were collected from a river in eastern Kochi Prefecture, Shikoku Island, Japan, and a natural spawning ground adjacent to the river. Mating behavior was observed 15 times at night, and distinguished into four stages: phase 1, tracking; phase 2, approaching; phase 3, amplexus; and phase 4, spawning. Egg diameters after water absorption were 2.1–2.3 mm, the spherical, demersal eggs having a light-yellow yolk, no oil droplets, and slight viscosity. Newly hatched larvae [3.3–4.9 mm in total length (TL)] had 46 (32 + 14) myomeres, two pairs of outer gill filaments on the cheek, and melanophores on the head. Notochord flexion started at 6.0–7.2 mm TL (wild individuals at 6.0–6.3 mm TL) and was completed at 8.8 mm TL (6.6 mm TL). The formation of membranous fins and full fin-ray complements were attained in the fin order pectoral, caudal, dorsal, anal, and pelvic, and caudal, dorsal, anal, pectoral, and pelvic, respectively. Some individuals (7.0–8.0 mm TL at the flexion stage) had free neuromasts, each with a short cupula, laterally on the caudal region. In addition, following the postflexion stage, some morphological differences between artificially bred and wild individuals were observed but could not be quantified due to the small sample size.

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筑後川流域は，平成29年7月九州北部豪雨により多大な被害を受けた．特に福岡県朝倉市から大分県日 田市にかけての右岸流域の支川においては，人的被害を伴う甚大な被害が発生した．大規模災害による生 態系への影響や，災害後の生態系の回復過程を明らかにすることは，筑後川だけでなく他の流域における 河川管理および生態系保全に有用であると考えられる．よって本研究では，筑後川において，魚類を対象 に，大規模災害後の分布状況を，環境DNA定量メタバーコーディングを用いて明らかにすることを試みた．環境DNA分析の結果，被災地支川の在来種の種数は対照区支川や本川に比べて少なく，在来種の環境DNA濃度は対照区支川に比べて低かった．また，外来種の種数は対照区支川や本川に比べて少なかった．これら の結果から，被災地支川では，在来種，外来種ともに，豪雨に伴う出水によって，種数および生物量が減少した可能性が示された．

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2008年に筑後川水系の小石原川上流部で得られたアカザ Liobagrus reini の卵塊を用いて，アカザの初期発育を記載した。採集時の状況より，卵塊は雄が保護していたと考えられた。1卵塊中に卵は69粒存在し，卵の直径は3.6±0.1 mm であった。孵化直後の体長は6.8 mm で，既に脊索後端部は上屈し，胸鰭の原基と上顎に1対の髭が存在し，開口していた。腹鰭の原基は孵化4日後・全長8.4 mm の時点で確認できた。胸鰭・背鰭・尻鰭の条数は孵化6日後・全長9.6 mm の時点で定数に達した。卵黄の吸収は，孵化後約14～15日の全長13.2～14.4 mm の時点で確認できた。尾鰭の鰭条数は，孵化16日後・全長14.6 mm の時点でほぼ定数になった。本種の卵径は，ナマズ，ビワコオオナマズ，イワトコナマズ，ギバチ，アリアケギバチ，ギギ，ネコギギ，などのナマズ目魚類と比べ卵径が大きかった。

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近年，計画から施工データ作成までの工程におけるデータ不連続性を解消するため，ゲームエンジンやiRICソフトウェアなどを活用した検討ワークフローが提案されている．また，iRICソフトウェア等の川づくり支援ツールを活用して治水・環境の一体的な河道設計が試行されており，その有効性の確認や課題が報告された．しかしながら，これらツールを複合して活用した一連の検討フローを実河川において適用した事例は少ないため，一級河川の川内川の菱刈地区を対象として，その有効性の確認などを行った．

ゲームエンジンの活用により，目標とする川づくりのイメージ共有を図ることができ,iRICによって治水面・環境面及び維持管理面の多面的な観点を評価した河道設計が実施できた．また，一連で同じ三次元データを用いることで効率的な検討が可能となること，ICT施工への受け渡しにおける留意点を確認した．

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災害発生時，被災河川の復旧や整備を検討するためには，河川生態系の目標設定が必要である．平成 29 年九州北部豪雨被災河川の目標設定のための参考資料を提示することを目的として，筑後川流域内の淡水魚類相データおよび 3 次メッシュスケールでの GIS データを使って，同流域内での各種の分布モデルを構築し，被災地周辺の GIS データをモデルに外挿することで，対象河川の潜在的な魚類相を推定した．34 種を対象にモデルを構築したところ，コイとナマズを除く 32 種で高い精度を伴うモデルが構築できた．23 種は標高を，13 種は地形の傾斜度を説明変数として選択した．また，3 次メッシュ内の水田面積や総河川長なども説明変数として多くの種が選択した．構築したモデルを使って，被災地である朝倉市，東峰村を流れる河川について，各種の出現の可能性を見積もったところ，河川性魚類ではカワムツ，タカハヤ，ムギツクの，氾濫原性ではドンコの潜在的生息河川数が多かった．絶滅危惧種では，河川性のスナヤツメ，ニホンウナギ，，アカザ，オヤニラミが 15 河川以上で，氾濫原性では数種のタナゴ類，アリアケスジシマドジョウ，ミナミメダカが 10 河川前後で，高い生息の可能性を示した．生息の可能性が高いと推定された種を各河川の潜在的魚類相構成種と仮定したとき，5 河川程度は河川性，氾濫原性を問わず，大半の魚種が生息可能な河川であると推定された．種数の多さは，標高 30 m 未満の区間を持ち，希少タナゴ類を含めた氾濫原性魚種が生息可能な河川であることに起因している．このような河川では直接被災した上流部だけでなく，下流部，そして，周囲の氾濫原水域にも配慮した整備が必要であると言える．河川性魚類に着目した場合，標高に対する応答曲線が 右下がり，凸型，右上がりと魚種ごとに様々であった．このことは，上流から下流まで，様々な種が生息し，流程に応じて魚類相が変化することを示している．それゆえ，河川性魚種の潜在的な種数が多い河川では，流程に応じて保全・再生対象となる魚種が変わることを考慮して，その復旧と整備を行う必要があると言える．

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