Estudio de la prevalencia de anisákidos zoonóticos en Sardina pilchardus (sardina de ley), Sardinella aurita (alacha), Sardinella maderensis (machuelo), Scomber colias (caballa) y Trachurus picturatus (chicharro)

Abstract

Anisakidae is a nematode family known as a danger for human health causing different stomach diseases (anisakidosis) and allergic reactions by the ingestion of L3 larvae stage individuals present in untreated raw (non-frozen) or undercooked marine fish, e.g.: anchovies marinated in vinegar, sushi. Anisakids presents a wide distribution and involves marine mammals as final hosts, zooplankton, fish and cephalopods as intermediate hosts, and humans act as accidental hosts. We investigated the prevalence of aquatic nematodes in the abdominal cavity and viscera of small pelagic fishes (SPF) caught by the artisanal purse-seine fleet of the Canary Islands. A total of 980 individuals were analysed between December, 2021 and March, 2022, during the routinely samplings performed in the EU Data Collection Framework including: Round Sardinella (Sardinella aurita, n = 201), Atlantic Chub Mackerel (Scomber colias, n = 478) and Chub Mackerel (Trachurus picturatus, n = 301). Helminths parasites were detected by the naked eye after biological sampling, extracted from the abdominal cavity and viscera, and stored in labelled vials in ethanol 70%. By morphological taxa they were distinguished between Acanthocephala and anisakids, and the latter ones were identified to the lowest taxonomical level as possible. A total of 77 anisakids were found in the samples. Based on these observations, S. colias presented the highest prevalence of these parasites, with the 10.8% of individuals parasitized by one or more individuals of anisakids, T. picturatus with the 5.3% vs. S. aurita which presented the lowest prevalence (0.5%), with only one parasitized individual. A positive correlation was observed between length parameter and parasitization by anisakids. Similar results were obtained in other researches from Canary Islands. The presence of this nematode should be a case of studies (ecological, spatial) for decreasing the risk of anisakiasis.