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

[摘要] 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 offish 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. Althoughparasite-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.

[学科分类] 生物科学（综合）

[关键词] Frequency distribution;Parasitic copepod;Sinergasilus polycolpus;Mortality;Silver carp;Hypophthalmichthys molitrix;Bighead carp;Aristichthys nobilis