The influence of temperature on the hemolymph CO_2 solubility coefficient (αco_2) and the apparent dissociation constant of carbonic acid (pKapp) in Mytilus coruscus was investigated. Mytilus coruscus hemolymph was equilibrated with standard CO_2 gas mixtures to obtain expressions for αco_2 and pKapp as a function of temperature. The relationship between αco_2 and temperature (T) is expressed as follows： αco_2 = 138.247 – 11.253 • T + 0.554 • T^2 − 0.0140 • T^3 + 0.000138 • T^4. The following relationship between pKapp and temperature was found： pKapp = 6.6407 – 0.01589 • T . The parameter units are ℃ for T and µM/L/torr for αco_2. These equations enable estimation of hemolymph αco_2 and pKapp at arbitrary temperatures and simple calculation of Pco_2 and [HCO_3^–].

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.