Does radioactive contamination affect the shell morphology of the pond snail Lymnaea stagnalis in the exclusion zone of the Chernobyl NPP (Ukraine)? Michael Zuykov • Dmitry Gudkov • Maxim Vinarski • Emilien Pelletier • David A. T. Harper • Serge Demers Published online: 3 September 2011 Ó Springer Science+Business Media, LLC 2011 Abstract A distinct external shell abnormality, coarse seam, was found in a high percentage of the pond snail Lymnaea stagnalis (L.) collected near Chernobyl Nuclear Power Plant (NPP), Ukraine. The negative cytogenetical and hematological effects of long-term irradiation on pond snails in the Chernobyl Exclusion Zone have been repeat- edly reported; consequently, it has been assumed that radioactivity may also affect shell morphology. However, due to the absence of this shell abnormality in pond snails collected from two radioactive sites in Russia, it can be concluded that the appearance of abnormal shells in snail population near Chernobyl NPP cannot directly be explained by the radioactive contamination. Keywords Shell abnormality Á Lymnaea stagnalis Á Radioactive contamination Á Environment Á Chernobyl NPP Á PA ‘‘Mayak’’ 1 Introduction There is considerable interest in the possible relationship between radionuclide contamination and pathological abnormalities in the ambient fauna and flora. We report here one case history from radioactive sites in the Ukraine and Russia (Fig. 1) involving large samples of a common gastropod mollusk. The pond snail, Lymnaea stagnalis, is a well-known and widespread freshwater gastropod species with a biennial life cycle occurring in Eurasia, North America, and parts of North Africa. Snails commonly scrape off food from the substrate, and this feeding mode is an easy pathway for the incorporation of various organic and inorganic contaminants into such organisms. Moreover, snails spend part of their lives on sediments, usually the most polluted component of aquatic ecosystems. For example, detailed study of reservoirs within the Chernobyl Exclusion Zone from 1998 to 2004 showed that about 90% of the total radionuclide content was concentrated in bottom sediments, while 2–10% occurred in the water mass and only about 1% in the biota (Gudkov et al. 2005). Therefore, the level of contaminants in snail shell and soft body, as well as cytogenetical and hematological effects of the long-term impact of low- dose irradiation in the snail population collected in the Chernobyl Exclusion Zone (Fig. 2), can be significant (Dzyubenko and Gudkov 2009; Gudkov et al. 2010a, b). Freshwater gastropods (e.g., lymnaeids) are among the taxa that are important for biomonitoring through the direct measurement of contaminants in shell and soft body material (Gomot 1998; Sala ´nki et al. 2003; Gudkov et al. 2009). Nevertheless, it is not clear whether contaminants do in fact affect shell morphology in pond snails due to a lack of adequate data, i.e., field observation supported by laboratory experiments. M. Zuykov (&) Á E. Pelletier Á S. Demers Institut des Sciences de la Mer de Rimouski (ISMER), Universite ´ du Que ´bec a ` Rimouski, 310, alle ´e des Ursulines, Rimouski, QC G5L 3A1, Canada e-mail: m.zuykov@mail.ru; Michael.zuykov@uqar.qc.ca D. Gudkov Department of Freshwater Radioecology, Institute of Hydrobiology, 12, Geroyev Stalingrada Ave., Kiev 04210, Ukraine M. Vinarski Museum of Siberian Aquatic Molluscs, Omsk State Pedagogical University, 14 Tukhachevskogo Emb., 644099 Omsk, Russia D. A. T. Harper Department of Earth Sciences, Durham University, South Road, Durham DH1 3LE, UK 123 Environmentalist (2011) 31:369–375 DOI 10.1007/s10669-011-9347-4