Vol. 78 2026

ARTICLES

Invisible Threats, Visible Changes: Microplastics Reshape Tadpole Morphology in Small Freshwater Ecosystems

Glorija Ćirković1& Rastko Ajtić1

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*1Department of Biology and Ecology, Faculty of Science, University of Kragujevac, Radoja Domanovića 12, Kragujevac, Republic of Serbia; E-mail: glorija.cirkovic@pmf.kg.ac.rs; rastko.ajtic@pmf.kg.ac.rs

https://doi.org/10.71424/azb78.1.003029

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Abstract

This study provides new evidence that microplastic (MP) exposure can alter morphological development in Rana dalmatina tadpoles, with effects most pronounced during early developmental stages. Tadpoles exposed to MPs at Gosner stage 25/26 showed a statistically significant increase in centroid size and greater morphological dispersion, suggesting heightened sensitivity to MP-induced stress during periods of rapid cell division and tissue differentiation. Principal component analysis (PCA) revealed a consistent trend: MP-exposed tadpoles tended to develop taller bodies and narrower posterior tails compared to controls. While these shape differences were not always statistically significant in later stages, their persistent occurrence points to a subtle but lasting effect of MP exposure. Increased centroid size among exposed tadpoles may indicate disrupted developmental processes or compensatory plasticity. In contrast, the absence of significant differences at stages 32/34 and 37/38 may reflect developmental resilience or a reduced impact of MPs as development stabilizes. The ingestion of MPs was confirmed in all exposed individuals, verifying the effectiveness of experimental treatments and strengthening the causal link between MP exposure and observed effects. The observed morphological variability could carry ecological consequences, potentially impairing swimming performance, predator avoidance, and overall survival. As amphibians are already threatened by multiple stressors, MP contamination represents an additional risk factor that could exacerbate population declines. These findings contribute to the growing recognition that environmental MPs can act as developmental disruptors in vulnerable taxa. Future studies should address the physiological mechanisms behind these effects, assess long-term fitness impacts, and explore interactions with other environmental stressors.

Key words

anuran larvae, aquatic habitats, geometric morphometrics, microplastics, Rana dalmatina

How to Cite
Ćirković G. & Ajtić R. 2026. Invisible Threats, Visible Changes: Microplastics Reshape Tadpole Morphology in Small Freshwater Ecosystems. Acta zoologica bulgarica 78.

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