Investigation on the Infection Status of Heterotrophic Nematodes in Marine Fish in the Dingzi Bay Area of Yantai

Yu Weixia; Zhang Hongchao

doi:10.3969/j.issn.1001-568X.2024.12.0012

Abstract：OBJECTIVE To investigate the infection of some marine fish with nematode larvae in Dingzi Bay of Yantai.The research aimed to analyze the infection characteristics across different fish species,examine the residents'awareness of nematode disease,and provide theoretical foundations for local prevention and control measures.METHODS Fresh marine fish were procured from the Dingzi Bay area at the pier in Yantai in November of 2021.The specimens were dissected for anatomical examination,and analysed microscopically to identify their morphological characteristics.Statistical analyses were conducted on the infection rates of nematode disease in various fish species and organs.Additionally,it conducted a survey among residents,involving questionnaires to investigate health knowledge and behaviors related to nematode larvae.RESULTS In terms of fish species,the infection rate of nematode larvae was recorded at 60.00%(12/20),and when analyzed based on the count of fish tails,the infection rate was 44.65%(96/215).The main parasitic site of nematode larvae varies among different fish species,and the infection rate of nematode nematodes varies among different parts of marine fish.Predominantly,grouper,mackerel and mackerel exhibited infections mainly in the abdominal cavity,and grouper,mackerel,mackerel primarily showed infections in the mesentery.A survey on related knowledge of heterophyophisoma infection among 300 coastal residents showed that only 40.00%of them had heard of the disease,while 76.00%of them usually cook fish with separate cutting boards for raw and cooked fish.CONCLUSION The infection rates of mackerel,anglerfish,and bighead catfish croaker in some marine fish in Dingzi Bay of Yantai.The low awareness of nematode disease among residents emphasizes the need for enhanced dissemination of relevant health knowledge and education,particularly in the context of preventing nematode disease through the consumption of cooked marine fish.