Traumatic Oral Lesions in Loggerhead Sea Turtles (Caretta caretta) Linked to Polychaete (Laetmonice cf. hystrix) Ingestion: A Case Report from the Northern Adriatic Sea

Oral cavity lesions in sea turtles, particularly Caretta caretta, are relatively rare, and are typically linked to infectious agents as well as anthropogenic factors, including ingestion of marine debris or fishing gear. This report describes a juvenile Caretta caretta found in the northern Adriatic Sea with severe oral lesions affecting the choanae, alimentary tract, and larynx. A comprehensive clinical and histopathological evaluation was conducted, which revealed traumatic injuries caused by the ingestion of a polychaete, Laetmonice cf. hystrix. Mucosal biopsies in the areas of spine penetration revealed the presence of strong sub-epithelial inflammation, characterised by micro-abscesses. In addition, around some fragments of spines, the formation of microgranulomatous lesions with a tendency to encapsulation was observed. Treatment protocol involved the removal of embedded spines and administration of a broad-spectrum antibiotic to prevent secondary infections. Recently, the detection in polychaetes of the aetiological agents of two newly emerging diseases of shrimps, suggests that these worms can be a host or/and passive carrier of these pathogens. This case study underscores the necessity to consider both biological and anthropogenic factors in diagnosing and managing oral lesions in marine turtles. Furthermore, it draws attention to the ecological risks posed by interactions between sea turtles and benthic organisms.