Anisakis infection in allis shad, Alosa alosa (Linnaeus, 1758), and twaite shad, Alosa fallax (Lacépède, 1803), from Western Iberian Peninsula Rivers: zoonotic and ecological implications

M. Bao*, M. Mota, D. J. Nachón, C. Antunes, F. Cobo, M. E. Garci, G. J. Pierce, S. Pascual

*Corresponding author for this work

Research output: Contribution to journalArticle

11 Citations (Scopus)
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Spawning individuals of allis shad, Alosa alosa (Linnaeus, 1758), and twaite shad, Alosa fallax (Lacépède, 1803), were sampled from three rivers on the Atlantic coast of the Iberian Peninsula (Ulla, Minho, Mondego) during 2008 to 2013 to assess the presence of the zoonotic marine parasite Anisakis spp. larvae. The results revealed that both shad species were infected by third-larval stage Anisakis simplex s.s. and Anisakis pegreffii. The latter is reported in mixed infections in both shad species of Western Iberian Peninsula for the first time. In A. alosa, the prevalence of Anisakis infection can reach 100 %, while in A. fallax, prevalence was up to 83 %. Infected individuals of the former species also often contain much higher number of parasites in theirs internal organs and flesh: from 1 to 1138 Anisakis spp. larvae as compared to 1 to 121 larvae, respectively. In general, numbers of A. pegreffii were higher than those of A. simplex s.s. Our results suggest that in the marine environment of the Western Iberian Peninsula, both anadromous shad species act as paratenic hosts for A. simplex s.s. and A. pegreffii, thus widening the distribution of the infective nematode larvae from the marine to the freshwater ecosystem. This finding is of great epidemiological relevance for wildlife managers and consumers, considering the zoonotic and gastroallergic threats posed of these parasites.

Original languageEnglish
Pages (from-to)2143-2154
Number of pages12
JournalParasitology Research
Issue number6
Early online date27 Mar 2015
Publication statusPublished - Jun 2015



  • Alosa
  • Anadromous
  • Anisakis
  • Freshwater
  • Gastroallergic
  • Iberian Peninsula

ASJC Scopus subject areas

  • Parasitology
  • Infectious Diseases
  • Insect Science
  • veterinary(all)

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