Ecological and molecular associations between neotropical wild felids and Taenia (Cestoda: Taeniidae) in the Atlantic Forest: a new report for Taenia omissa

Ecological associations between wild felids and parasites from the Taeniidae family are related to predator–prey interactions, where felids act as definitive hosts while their prey, herbivores and/or omnivores, act as intermediate hosts. In the Atlantic Forest, six neotropical felid species coexist in sympatry, but the ecological parasite-host interactions remain poorly studied. Taenia omissa is a tapeworm that parasitizes cougars ( Puma concolor ) as its only definitive host and their ungulate prey as intermediate hosts. The aim of this study was to identify tapeworms present in road-killed fauna using both molecular and morphological characteristics and their predator–prey relationship. Adult tapeworms found in a cougar, a jaguarundi ( Herpailurus yagouaroundi ), and two ocelots ( Leopardus pardalis ); and metacestodes found in a red brocket deer ( Mazama americana ) and a wild guinea pig ( Cavia aperea ) were analyzed. Through morphological analysis of rostellar hooks and molecular analysis of the mitochondrial genetic marker cox1 , Taenia omissa adult individuals were identified in the cougar, and metacestodes in the red brocket deer, proving the existence of a full host-parasite life cycle in the Atlantic Forest region. This new report reveals the southernmost record of T. omissa and broadens its geographic distribution. In addition, isolates of the Taenia genus divergent from those described so far in molecular databases were reported and suggested a wild cycle that involves the jaguarundi and agouti (Dasyprocta asarae ) as definitive and intermediate hosts, respectively. These results highlight the complexity of the tapeworm population in the region and the need to study it with both morphological and molecular approaches.