In situ assessment of stress level in perch during cryogenic waterless live transportation using multisource impedance electrodes

Traditional methods for determining stress level in live fish rely on biochemical tests such as blood glucose and cortisol measurement. However, these methods are plagued by time-consuming and labor-intensive procedures. To address this issue, this study introduces an electrical impedance spectroscopy electrode system based on three different materials and four distinct shapes. Additionally, an electrical impedance spectroscopy measurement system is developed for monitoring the stress level of perch during cryogenic waterless live transportation. The experiments conducted aim to assess the impact of various electrode materials and shapes on measurement accuracy while effectively gauging the stress level of perch by monitoring changes in muscle contraction. The findings reveal that the lamellar ipsilateral copper electrode stands out as the most effective choice for monitoring perch stress level. Furthermore, the stress level in perch is categorized into five stages: acute stress, in vivo regulation stress, adaptation stress, cumulative stress, and the near-death stress within 12 h. This categorization is achieved through data mining and morphological characteristic parameter extraction, aligning closely with standard blood glucose data. The stress level prediction model, based on an artificial neural network (ANN), demonstrates remarkable accuracy, achieving a prediction rate of 91.66%. This result underscores the effectiveness of the system. This study contributes to enhancing the health management of live fish during transportation and represents a significant step towards advancing smart fisheries development.