Triacid staining solution (neutral mixture) contains dye complex. Here, we speculate on the structure and characteristics of the dye complex in various triacid staining solutions. It was inferred that the dye complexes in the Ehrlich (methyl green + 2 acid fuchsin, methyl green + 2 orange G, methyl green + acid fuchsin + orange G), Romanowsky (eosin + methylene blue), and Pappenheim (eosin + methylene azure) triacid stains behave as acidic dyes, and that the dye complexes do not dissociate against weakly acidophilic objects, resulting in staining with a complex color (purple). Therefore, it can be said that the objects to which the dye complexes bind without dissociation do not need to be basophilic. When the stained material is highly acidophilic or basic, the dye complex dissociates, and the acidophilic object is stained by the acidic dye and the basiophilic object by the basic dye. The dissociation of dye complexes depends on the degree of acidophilicity and basophilicity of the stained material, and the dissociation depends on the types of dye composing the dye complexes. The dye complex in a triacid stain can be defined as a purple acidic dye in which the bonds between the acidic and basic dyes in the complex can be broken, depending on the acidophilic and basophilic strength of the object.

In 2023, a new seafood cracker named Bakan-Senbei was commercialized in collaboration with National Fisheries University and two private companies. The standout feature of Bakan-Senbei is that it is made from low-utilized/unutilized fish, which contributes to the Sustainable Development Goals. Focusing on this feature, two types of questionnaires（A and B）were implemented to evaluate visitors’ perception of its quality at the Osaka Seafood Show held in February 2024. In questionnaire A, we investigated the potential demand price after providing product information. In questionnaire B, the potential demand price was examined by intentionally excluding only the material information, and then the potential demand price was examined while first excluding material information； then it was examined again after only providing material information and excluding lust time. Interval regression analysis revealed no significant difference between the potential demand prices from the two questionnaires. This result revealed that consumers did not recognize the added value converted into monetary value as perceived quality of the use of low-utilized/unutilized fish. This result indicated that consumers did not perceive the added value of using low-utilized /unutilized fish as translating into monetary value in terms of quality. Conversely, there was a significant difference between the two groups regarding the provision of material information in questionnaire B. This result was supported by the outcome that 21% of respondents raised the rank of potential demand price due to the provision of material information. We estimated the increase price to be 5.5 yen, which was 4.5% of the list price. It was suggested that the added value could be improved by providing important information.

イガイの呼吸機能，特に酸塩基平衡を評価するため，イガイ閉殻筋から採取したヘモリンパ液を用いて，二酸化炭素溶解度（αco_2）と炭酸解離恒数（pKapp）に及ぼす温度の影響について調査した。各実験温度において，イガイのヘモリンパ液を二酸化炭素標準ガスと平衡させ，pHと全炭酸含量を測定し，温度（T）とαco_2あるいはpKappとの関係を分析したところ，以下の関係式を得た。αco_2 = 138.247 – 11.253 • T + 0.554 • T^2 − 0.0140 • T^3 + 0.000138 • T^4，pKapp = 6.6407 − 0.01589 • T（αco_2： µM/L/torr； T： ℃）。これらの式により，任意の温度でイガイのヘモリンパ液におけるαco_2とpKappの推定が可能となった。これら推定値を用いれば，微量なヘモリンパ液の二酸化炭素分圧や炭酸水素イオン濃度を任意の温度で把握することができるだろう。

Viral edema of carp is caused by Carp edema virus and is a major carp disease listed on the WOAH list of emerging infectious diseases. However, an effective experimental infection method that can control virus copy number has not been established. In this study, we compared three experimental infection methods：immersion infection using gill suspensions from diseased fish (immersion method), infection by rearing water from diseased fish (rearing water method) and co-infection method. Cumulative mortality in the immersion groups ranged from 40 to 60%, while that in the rearing water infected and co-infected groups ranged from 80 to 100%. The rearing water method can be used to control the viral DNA copy number and to perform experimental infections when frozen storage is possible. Thus, we performed the same experimental infection using frozen rearing water and found no disease or mortality, indicating that stable experimental infection using the rearing water method is difficult. The immersion method has a lower mortality rate than the other two methods, and it requires a large amount of gill tissue because of the low number of virus DNA copies that can be obtained from the gill tissue. However, it is possible to control the number of virus DNA copies and to preserve the gill tissue suspension by freezing. Therefore, the immersion method was considered the most suitable for stable experimental infection under the same conditions,

On board research were carried out for investigate the quality of fishing boat under the circumstances, which are observed experimentally in ordinary use on the seas. The present research was prepared in the ordinary operation of maintenances in dock. As the results, it was revealed that fuel consumption was reduced remarkably by cleaning bottom of ship hull, propeller and rudder. And in the condition of foul of ship bottom before cleaning, reducing the rotation speed of the main engine capable of largely improving a fuel efficiency, in comparison to the rate of decrease in ship speed.