Terrestrial exposure to microplastics in an endangered salamander (Lyciasalamandraantalyana)

Microplastics (MPs) are increasingly reported from a wide range of environments, yet information on terrestrial amphibians remains scarce. In this study, we investigated the occurrence and characteristics of MPs in the gastrointestinal tracts of the endemic and endangered terrestrial salamander Lyciasalamandra antalyana from Türkiye. A total of 67 specimens were analyzed, and MPs were detected in 34 individuals (50.7%), with 46 particles identified in total. The overall median MP abundance was 1 particle per specimen (range: 0-8). No significant differences in MP abundance were detected among females, males, and juveniles, and no significant relationships were found between MP abundance and body size variables. Five polymer types were identified, with polyethylene terephthalate (PET, 67.4%) being the most abundant, followed by ethylene-vinyl acetate (EVA, 13.0%) and polyacrylonitrile (PAN, 10.9%). Most particles were fibers (93.5%), whereas fragments were rare. The predominance of PET and fibers may indicate potential terrestrial sources, likely related to synthetic materials and diffuse anthropogenic inputs. Navy blue particles predominated, and a significant association was observed between particle shape and color. The mean particle size was 219.04 ± 21.95 μm, with particles distributed across all size classes. These findings provide baseline evidence of microplastic occurrence in a habitat-restricted terrestrial amphibian and contribute to a better understanding of microplastic contamination in terrestrial ecosystems.