Influence of Haemobaphes cyclopterina and H. intermedius (Copepoda) on Arctic cod (Boreogadus saida) and tidepool sculpins (Oligocottus maculosus), respectively

A study was conducted to determine the prevalence and effects of two species of blood-feeding copepods on their definitive fish hosts, viz. Haemobaphes cyclopterina parasitizing Arctic cod (Boreogadus saida) and H. intermedius infecting tidepool sculpins (Oligocottus maculosus). Infected and uninfected Arctic cod and tidepool sculpins were captured by SCUBA and dip net in the northwest Atlantic and northeast Pacific, respectively. Biological variables such as condition factor, hepatic somatic index, gonadal somatic index, and haematocrit were compared between the two groups of Arctic cod of both sexes, whereas only condition factor was compared in the two groups of sculpins of both sexes. Prevalence of H. cyclopterina (8%) was considerably lower than that of H. intermedius (46%). This difference is probably associated with the hosts' behaviour, as the Arctic cod is pelagic whereas the tidepool sculpin is restricted to the littoral zone, where infections are probably acquired. Infected Arctic cod of both s...