YU Zhe1, 2, 3, JIANG Linyuan2, WEN Luting2, QIN Qijin1, 3, LI Yijian2, WEN Jiayan1, 3
In the freshwater snail product classification and processing scenario, accurately and efficiently identifying the sexes and dead features of Cipangopaludina cahayensis is crucial for the quality classification and grading of freshwater snail products. Distinguishing between male and female individuals allows for targeted selection of high-quality parents for snail seed breeding. Timely removal of rotten dead snails is important for maintaining water quality in aquaculture and disease prevention. Currently, the methods for identifying the sexes and dead features of Cipangopaludina cahayensis mainly include: 1) distinguishing between males and females based on differences in antennae observed in their natural state; 2) distinguishing between male and female glands under strong light transmission and observing the internal shrinkage of snails after death to differentiate. However, these methods suffer from issues such as high workload, subjectivity, high time costs, low detection efficiency, and high false detection rates. In response to the demands of modernizing China's fisheries, achieving automation and intelligence in the classification of male and female individuals and dead features of Cipangopaludina cahayensis is of significant importance for improving the technological development of freshwater snail factory farming and aquatic product classification and processing. Therefore, how to achieve accurate identification and rapid detection of the sexes and dead features in the processing of snail products is a pressing issue that needs to be addressed in the automation of quality classification and grading operations for Cipangopaludina cahayensis. Cipangopaludina cahayensis has a relatively late development in automated aquaculture compared to other aquatic organisms, with limited targeted research on intelligence. Additionally, existing algorithmic literature focuses solely on the detection of the phenotypes of freshwater snail shells, neglecting considerations such as model lightweighting, unbalanced detection accuracy, and real-time detection speed. The detection effectiveness of the algorithms for distinguishing the sexes and dead features of Cipangopaludina cahayensis still remains inadequate. In summary, this study adopts the YOLOv8n model as the base model and proposes a Cipangopaludina cahayensis male-female and death feature detection algorithm based on AP2O-YOLOv8. This research aims to provide a theoretical foundation and reference for the automation and intelligence of processes such as quality classification and grading of Cipangopaludina cahayensis products. In terms of model design, this study introduces the P2 layer for small target detection, incorporates larger-scale feature maps containing more information about snail target positions and inter-class local features, and combines the ASF-YOLO structure and C2f-OREPA module to further enhance the algorithm's multi-scale feature fusion capability and real-time detection speed. This approach allows the model to have higher detection performance while being more lightweight and efficient. The improved algorithm in this article integrates three enhancement schemes. Compared to the original YOLOv8, its precision (P), recall (R), and mean average precision at IOU 0.5 have increased by 2.1%, 2.6%, and 5.6% respectively. The parameter size has decreased from 2.9MB to 2.1MB, a reduction of 27.6%. The frames per second (FPS) have increased from 180 to 226, a 25.6% improvement. The AP2O-YOLOv8 model proposed in this article for the detection of male and female Cipangopaludina cahayensiss, as well as their vital status, significantly enhances the detection accuracy of different features of Cipangopaludina cahayensiss compared to the original benchmark model. Simultaneously, it effectively reduces the complexity of the model, greatly increasing real-time detection speed. This study provides new ideas and methods for the classification and detection of male and female, live and dead Cipangopaludina cahayensiss, helping further advance the automation and intelligence upgrade of the quality classification and processing process of Cipangopaludina cahayensiss.