From parasite to pathology: A novel manifestation of cestodiasis in Octopus maya

This study aimed to characterize the effects of Prochristianella sp. infection (Cestoda: Trypanorhyncha) in the Octopus maya, with focus on tissue pathology, immune response, and potential implications for host health.

Molecular analyses of 28S ribosomal DNA were performed to confirm the identity of collected parasites from the buccal mass of octopus hosts. Macro- and microscopic observations of O. maya tissues, hemocyte counts, and histological analyses were conducted to assess the damage caused by the infection. Comparisons were made between naturally infected octopuses from Río Lagartos, Yucatán (the affected group), and minimally infected octopuses from Campeche (the control group) to establish a reference baseline for health and tissue morphology.

Prochristianella sp. 1 was the only parasitic species infecting the buccal mass of octopuses collected from Río Lagartos, contrasting with the absence of the parasite in octopuses from Campeche, which were used as a reference group to characterize the infection. The affected group exhibited an undescribed capsular structure on the superior mandibular muscle of the buccal mass, containing cestodes and mucus and associated with tissue alterations, such as fibrosis, hemocyte infiltration, and focal necrosis. These findings led to the provisional designation of this condition as "myocestodiasis in cephalopods."

This work provides new findings on helminth-induced pathologies, generating hypotheses about the underlying mechanisms in infected cephalopods. The study highlights the importance of multidisciplinary approaches to understanding host-parasite interactions. Furthermore, it lays the groundwork for managing and conserving the O. maya, an important marine resource of the Yucatán Peninsula.