Nematode Infections in Commercially Important Squid Species: Distribution Patterns and Food Safety Issues

Introduction: Cephalopods represent a valuable fishery resource worldwide and play a crucial role in the marine food chain both as predators and prey but also as paratenic hosts for the transmission of Ascaridoids, including zoonotic nematodes of the Anisakidae family. This study aimed to assess the presence, tissue distribution and species composition of zoonotic parasites in four squid species marketed in Italy, coming from four different FAO areas. Methods: A total of 238 squid specimens, Illex sp., I. coindetii, I. illecebrosus and Todaropsis eblanae, were caught across four FAO areas and examined using both visual inspection and the UV-press method. The collected larvae were identified by morphological and molecular methods. Results: Third stage larvae of nematodes were detected in 22.3% of the squids (18.8% Illexsp., 18.3% I. coindetii, 48.8% I. illecebrosus and 23% Todaropsis eblanae), with Anisakis simplex (s.s), A. pegreffii, Hysterothylacium spp. and Lappetascaris spp. being identified through morphological and molecular analyses. The UV-press method has proved to be significantly more effective than visual inspection. Additionally, the lack of molecular data on Raphidascarididae species, particularly Lappetascarisspp., complicates taxonomic classification, emphasising the need for an integrative taxonomic approach combining morphological and genetic methods. Conclusion: Given the increasing consumption of raw and undercooked cephalopods, these findings highlight the importance of monitoring zoonotic parasites and improving molecular techniques to enhance food safety regulations and minimise health risks to consumers.