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This study aims precisely to explore the main reasons that explain the risk that still exist in the sector, in order to evaluate them, provide tools for risk assessment and guidelines to avoid them.

Specific objectives:
O1. To design experimental methods to evaluate, with direct evidence, the infective capacity of anisakis in sea bream.
O2. To determine the acceptance, susceptibility and permanence of anisakiasis in sea bream (long-term studies and health implications). T
O3. To design a new experimental protocol to evaluate, with direct evidence, the infective capacity of anisakid nematodes using mollies.
O4. To determine the acceptance, susceptibility, and permanence of anisakis in the molly for long-term studies.
O5. To provide optimized experimental models of infection in fish useful for experimental studies in seawater and freshwater.
O6. To design new non-experimental methods to assess the infectivity of anisakis.
O7. To evaluate and optimize anisakis inactivation routines in bait used in aquaculture feed.

A1 Disseminate and communicate the project’s findings; Transmission of good practices to consumers and related agents and entities

A2 Conduct a study of the habitat, infection, and longevity of anisakis within the sea bream cavity

A3 Experimentally evaluate the susceptibility of molly to anisakis by voluntary or introduced ingestion

A4 Perform an infection and habitat study of anisakis within the molly cavity

A5 Optimize protocols for keeping fish (gilthead bream and molly) and infection in anisakids to check the infective capacity of nematodes after sanitary treatments or inactivation routines

A6 Develop a new anisakis viability assessment protocol based on macroscopic and ultrastructure damage

A7 To evaluate, using the methods previously developed, the effectiveness of the procedures used to inactivate the anisáchidae of the bait used in tuna culture

The main scientific task developed has been to analyze the susceptibility of sea bream and mollies when infected with anisakis. Numerous dissemination tasks have also been carried out, the most numerous being in this project. We have been able to disseminate in talks and workshops, on social networks, on websites, radio, newspapers, in aquaculture magazines and in scientific congresses, which reflects the diversity of fields.

In the development of the project, sea bream and mollies were exposed to live anisakis, free in water, as well as injected with food in the stomach. A viability follow-up was carried out during the first two months, confirming the good condition of the fish. Thanks to these results, we know that sea bream is infected and is a good model of infection. Also, it has been observed that molly can actually become infected and that it accepts anisakis as free-form food. However, it is more susceptible to infection and the method of ingestion must be refined. In February, mollies were exposed to live anisakis, free in water, as well as injected with food into the stomach. Unlike sea bream, greater impact was observed in mollies.

A viability follow-up was carried out until the end of the experiment, confirming the survival of infected mollies. This implies that the critical period is that of infection. The fish were successfully infected in February, followed up until the end of the study. It has been observed that molly and sea bream become infected with the parasite, but that sea bream is much less vulnerable to handling. The results indicate that sea bream is the safest infection model, but the infection protocol in molly needs to be improved due to its better maneuverability.

Finally, live anisakis extracted from blue whiting were identified with molecular and morphological methods and subjected to temperature and dehydration conditions. Subsequently, their appearance, mobility and ultrastructural damage were analyzed, using scanning electron microscopy. Fish have been placed in different containers, to vary the drying by sublimation in cold storage. They have been subjected to different freezing times, according to instructions from the tuna company. Subsequently, the specimens have been studied macroscopically, with a magnifying glass and in scanning electron microscopy.

The results of this project have made it possible to analyse the vulnerability to anisakis in sea bream aquaculture and to look for ways to carry out experimental studies in fish.