RESUMEN
The European conger, Conger conger, is a benthic marine fish species with a geographical distribution extending through the northeastern Atlantic and the Mediterranean. Despite being extensively distributed and widely appreciated by Spanish consumers, studies regarding parasite presence in this fish are scarce. In the present work, a hundred and eight specimens from the Mediterranean coast of northeastern Spain (Catalan waters) were surveyed for the presence of nematode parasites. Several species were morphologically identified: third-stage larvae of Anisakis type I (sensu Berland, 1961) (n = 131), third-stage larvae of Anisakis type II (sensu Berland, 1961) (n = 18), third- and fourth-stage larvae and adults of Hysterothylacium spp. (n = 48), adults of Cucullanus sp. (n = 391), and adults of Cristitectus congeri (n = 69). Moreover, some fish and decapode species were also observed as part of the host's diet, with the most detected preys being Micromesistius poutassou, Sardina pilchardus, Macropipus sp., and Goneplax rhomboides. This represents the first survey of nematode parasites infecting C. conger from the northeastern Spanish Mediterranean waters. Among the parasite species detected, the presence of Anisakis species should be highlighted as the ingestion of C. conger parasitized with these larvae could potentially lead to anisakiasis in consumers.
RESUMEN
This research provides an evaluation of the quality and health status of some locally abundant fish species, usually otter-trawl bycatch species. The study was conducted in the southern and eastern Spanish Mediterranean coast. Mean concentration of heavy metals in muscle and parasitisation indices showed moderate levels. Higher lead concentration was found in fish from the western Alboran and arsenic, cadmium and mercury were more present on fishes from the eastern Alboran area, although most species analysed contain moderate levels of heavy metals in muscle. Concerning parasitisation, F. Anisakidae nematodes were present in all the species, except sardine. Only mercury showed a positive relationship with parasitisation. We also considered three feeding guilds. Metal mean concentrations were higher in benthivores and more littoral fishes. Pelagic planktivores species are the healthiest and the more suitable for consumers from the sanitary point of view.