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土砂の透水性に着目したイカナゴ夏眠場における粒径の下限の推定
No full textUsing the effective diameter D20 used in Creager’s formula, which is most used to calculate hydraulic conductivity, we evaluated the lower limit of particle size in aestivation sites of Japanese sand lance Ammodytes japonicus (DUNCKER & MOHR). We investigated the relationship between the number of Japanese sand lance collected in their aestivation sites and the effective diameter D20 of the bottom sediment. As a result, the number of Japanese sand lance in the sites where the effective diameter D20 is 0.2 mm or less, where the water permeability drops sharply, was significantly reduced. This suggests that the grain size (pore size) must be large enough to ensure breathing during aestivation as a condition for the establishment of aestivation of in the Japanese sand lance. It was also shown that effective diameter D20 of 0.2 mm or greater, where the aestivation sites of Japanese sand lance are established, generally corresponds to 0.3–4 mm or greater in D50 (median diameter). which are the most used indicators of the grain size distribution of the bottom sediment.journal articl
salmon情報 No.19
Full text link編集：水産研究・教育機構 水産資源研究所 さけます部門増殖事業におけるサケ・マス類の回遊と生理（伴真俊）
稚魚が食われて起こること（長谷川 功・本多健太郎・佐々木 系）
続・サケの母川回帰精度について（福澤博明・森下匠・外山義典・加藤雅博・今井謙吾）
日本におけるベニザケ人工ふ化放流の歴史（髙橋昌也）
さけます関係研究開発推進会議（佐藤俊平・長谷川 功）
さけます報告会（髙橋昌也）
第31回北太平洋溯河性魚類委員会（斎藤寿彦）
なぜ魚の福祉に配慮するのか（小倉裕平）
さけの遡上(かえ)る川-5 標津川（北海道）（市村政樹）
北太平洋と日本におけるさけます類の資源と増殖（外山義典）other periodica
Feeding behavior characteristics and relationship between standard length and size of scrape marks of ayu, Plecoglossus altivelis altivelis, observed in aquaria
Full text linkCharacteristics of the feeding behavior and relationship between the standard length (SL) and the size of scrape marks of ayu Plecoglossus altivelis altivelis were studied using 123 cultured specimens in aquaria. Feeding behavior was observed individually, 116 specimens (94%) have mouth laterality for feeding. Also, feeding behavior were found two types. The first was eating the algae directly from the shelter in 91 specimens (78%). The second left the shelter and ate the algae after changing direction back to the shelter (22%). One side of the lower jaw when feeding on the acrylic plate side was turned downward and the other side of the jaws was closing. On the scrape marks, 11 to 14 and 11 to 13 level lines were visible caused by the upper and lower jaws and the algae was not scraped between the upper and lower parts. The comb–like teeth groups are arranged as 13 to 14 rows and 12 to 14 rows on the upper and lower jaws, respectively. Therefore, it is suggested that they use almost all of the comb–like teeth groups except the back teeth row on the upper and lower jaws for feeding. The lengths of upper and lower jaws were found to have power regression with the SL, respectively. Also, the relationship between the SL and full width of the scrape marks (FWSM) was: FWSM = 0.3939SL0.6767 (R2 = 0.8392, 64-212 mm SL).編集：水産大学校departmental bulletin pape
Morphological and cytochemical characteristics of monocytes from lampreys: Reevaluation of Kiyono’s literature on the identification of hagfish monocytes
Full text linkThe monocytes of lampreys [Lethenteron camtschaticum (adult), L. reissneri (adult), L. hattai (adult, ammocoetes)] were round or oval, low nucleus/cytoplasm ratio, and have striated (two-layered) granules (MoG). The MoG consisted of a basophilic inner layer (L0) and a chromophobic outer layer (L1). The L0 were positive for acid phosphatase, α-naphthyl acetate esterase, naphthol AS-D chloroacetate esterase and Sudan black B. Also, the L0 showed orthochromatic (blue) with toluidine blue. However, ꞵ-glucuronidase, α-naphthyl butyrate esterase and peroxidase were not detected in the monocytes, which were negative for periodic acid Schiff reaction, alcian blue, Sudan III, and oil red O. Kenji Kiyono reported the two types of monocytes (as blood histocytes), real and dubious monocytes, from the blood of hagfish Eptatretus burgeri. He observed both monocyte types in grown-up hagfish, but only real monocytes in undeveloped (details not stated) hagfish. His real monocytes in undeveloped hagfish were speculated as the monocytes of lamprey (mistaking the specimen), and the real monocytes in grown-up hagfish as poorly stained neutrophils. The dubious monocytes of Kiyono were considered as the real monocytes of hagfish.編集：水産大学校departmental bulletin pape
Species-specific and size-related spatial distribution, and feeding substrates of goatfishes (family Mullidae) in relation to environmental characteristics on an Okinawan coral reef
No full textGoatfishes (family Mullidae) are a common fish group and important fishery target in coral reefs. This study examined the species-specific and size-related spatial distribution of seven goatfish species in relation to environmental characteristics as well as their variations in substrate utilization for foraging in an Okinawan coral reef. All size classes (5–32 cm in total length) of four species (Parupeneus barberinoides, P. barberinus, P. pleurostigma, and Mulloidichthys flavolineatus) showed greater densities at sites with a greater coverage of sand in inner reefs and significant positive utilization of sand as feeding substrates. For P. multifasciatus, smaller (≤ 10 cm) and larger-sized individuals (11–25 cm) showed greater density at sites with a greater coverage of macroalgae in inner reefs and greater coverage of coral rubble in exposed and inner reefs, respectively. Parupeneus multifasciatus also showed positive utilization of rock and coral rubble as feeding substrates. Most size class individuals of P. cyclostomus (≤ 10 cm and 16–25 cm) and M. vanicolensis (11–25 cm) showed greater densities at sites with a greater coverage of rock, branching Acropora spp. and other corals. Parupeneus cyclostomus also utilized rock, dead corals, and coral rubble as feeding substrates but such utilization was not significant. Mulloidichthys vanicolensis showed no feeding behavior. This study indicated that a greater coverage of sand, coral rubble, and rock has positive effects on the spatial distribution of goatfish assemblages, suggesting that the coverage of non-coralline substrates is an important indicator for selecting candidate marine protected areas for maintaining the diversity of goatfish species.journal articl
Differences in profitability and profit structure of inland fisheries cooperative multiplication projects based on fishing ground
Full text linkAfter reviewing fiscal year 2017 business reports of Japanese inland fishery cooperatives (JIFCs), we divided JIFCs into seven categories based on the species they target and the type of fishing ground they use. We then use the rate of return in stocking among types. In addition, we analyzed differences of income by business aside from fishery management and external supports in total income. The results show profit margins of stocking depended on recreational fishing fee except two categories that did not dealing with Ayu and salmonids. Profit margins of these two types were relatively higher despite receiving relatively low fees for recreational fishing. These results suggest that the cost of stocking Ayu and salmonid are relatively expensive.全国の内水面漁協を，2017事業年度の業務報告書を用いて，漁業権魚種と河川 /湖沼の別によって 7類型に類型化した。増殖経費に対する賦課金・行使料・遊漁料の収入の比率を漁業権収益率として，これによって各類型の増殖事業の収益性を分析し，また経済事業の収入と補償金等の収入が総収入に占める割合について分析した。その結果，遊漁料収入が多いほど増殖事業の収益性が高いが，アユおよび渓流魚を含まない漁協では遊漁料収入が少ないにもかかわらず増殖事業の収益性が高いことが明らかとなった。この結果から，アユおよび渓流魚では増殖経費が高いことが示唆された。ファイル名末尾に”_abs_j”のファイルは和文要旨journal articl
