Anisakids (Nematoda: Anisakidae) from ringed seal, Pusa hispida, and bearded seal, Erignathus barbatus (Mammalia: Pinnipedia) from Nunavut region

Abstract

As many Arctic fish species are intermediate hosts of anisakids, they are present in the diet of the ringed seal, Pusa hispida, and the bearded seal, Erignathus barbatus. Parasitic nematodes from the stomachs of 66 seals caught in the Nunavut region (Canada) from two communities (Arviat and Sanikiluaq) from October 2007 to January 2008 have been examined in order to identify the epidemiological risk for Inuit communities who consume traditional food. In Arviat 2428 anisakids were observed in 37 seals, while in Sanikiluaq 316 Anisakidae were isolated from 29 seals. The worms were treated with a host tissue, washed in deionized water and stored until analysis in 70% ethanol. The parasites were divided into three parts. The anterior and posterior parts were stored in 70% ethanol containing 5% glycerol and were examined using a light microscope by evaporation of the ethanol/glycerin mixture. The central parts were prepared for molecular identification by fixing in 70% ethanol. Using the polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) method, the following members of the family Anisakidae were identified: Contracaecum osculatum A and C and Pseudoterranova bulbosa. In the studied material, more adult worms were noted than larval stages. The most numerous nematodes were P. bulbosa, and mixed infection was observed. The mean prevalence of anisakids infection was 43.2% in the Arviat and 37.9% in the Sanikiluaq communities.