DAO 48:237-239 (2002)  -  doi:10.3354/dao048237

Mortalities induced by the copepod Sinergasilus polycolpus in farmed silver and bighead carp in a reservoir

Gui T. Wang1,*, Wen X. Li1, Wei J. Yao1, P. Nie1,2

1Laboratory of Fish Diseases, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei Province, PR China
2State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei Province, PR China

ABSTRACT: The frequency distributions of the parasitic copepod Sinergasilus polycolpus were examined in silver carp Hypophthalmichthys molitrix and bighead carp Aristichthys nobilis during a disease outbreak of the 2 species of fish in a reservoir in China. The mean abundance of the copepod was positively related with host length and age, and the overdispersion of the copepod in both silver and bighead carp was fitted well with negative binomial distribution. Although parasite-induced host mortality was observed, a peaked age-parasite abundance curve was not detected in the present parasite-host system. It is also proposed that this peaked age-abundance curve is unlikely to be observed in its natural host populations.


KEY WORDS: Frequency distribution · Parasitic copepod · Sinergasilus polycolpus · Mortality · Silver carp · Hypophthalmichthys molitrix · Bighead carp · Aristichthys nobilis


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