The number of open cases of stomach ulcers caused by parasitic worms of the genus Anisakis, several species of Dolphin near the Atlantic coast of Spain, in the years 2017-2018 significantly increased compared to the years 1991-1996, reported in the Journal of Helminthology. Probably increased the number of these worms, but it is also possible that the General deterioration of the habitat conditions of cetaceans made more vulnerable.
Roundworms of the genus Anisakis and closely related species are parasitic on marine animals. Their larvae molt in a variety of fish and squid and other invertebrates. They eat cetaceans, and in their stomachs anisakis continue shedding: with L3 larval stage, they move on to L4 (last juvenile stage), and then become sexually Mature and reproduce. The worms attach to the stomach wall, which often formed ulcers and granulomatous tissue formed. In some cases, possible peritonitis and death of the animal host.
Anisakis affect humans. Once in the digestive system, their larvae can cause allergic reactionseven when dead. Live worms have the ability to make holes in the walls of the gastrointestinal tract and migrate into the abdominal cavity, which leads to serious negative health effects. Therefore it is necessary to study more the spread of anisakis among marine animals, to understand what risks it carries for people.
Researchers from several Spanish research institutions led by Claudia Ponce Bordas (Claudia Pons Bordas) from the University of Valencia rated the proliferation of gastric ulcers, the cause of which were the worms of the genus Anisakis, cetaceans that have stranded in the Autonomous community of Galicia from 2017 to 2018. They obtained data compared with results of earlier studiesin which their colleagues have collected similar information for the years 1991-1996.
The researchers tested the status of 59 stomachs of cetaceans such species: bottlenose Dolphin (Tursiops truncatus, 7 individuals), common Dolphin (Delphinus delphis, 43 individuals), striped Dolphin (Stenella coeruleoalba, 5 individuals), harbour porpoise (Phocoena phocoena meridionalis, 3 individuals), common whale (Globicephala melas, 1 individual). They classify ulcerative lesions of the walls of the stomach, considered their average number per animal and determined what types of worms present in each individual and what age they were.