Maternal Transfer of Metals in Non-Native Mysterysnails

Abstract:

Aquatic snails accumulate metals in their tissues and shells based on environmental exposure. Because they possess a calciferous shell, snails can offload metal contaminants into their shells during development, reducing contaminant concentrations in more sensitive tissues. This process may be exacerbated in snail species that are ovoviviparous, such as non-native mysterysnails. The formation of juvenile shells within the mother’s brood pouch may allow for maternal transfer of metal contaminants to offspring. However, little is known about this process in mysterysnails. The objective of the current study was to quantify maternal transfer of metal contaminants in non-native mysterysnails collected from Pennsylvania waters. Non-native mysterysnails were collected from six locations, including Presque Isle State Park, Lake Arthur, Pymatuning Reservoir, Lake Canadohta, Edinboro Lake, and Lake Pleasant. After a 24 h depuration period, adult snails were dissected, and gravid females were isolated for analysis. Maternal tissues and offspring within the brood pouch were digested, and metal concentrations were quantified via an inductively coupled plasma mass spectrometer. We found that mothers are capable of offloading metals to their offspring, but offspring exhibit different patterns of accumulation depending on the metal ion. Both copper and lead were significantly correlated in offspring and maternal tissues, suggesting these ions may be substituted for essential elements such as calcium during offspring development. Maternal transfer of metals may influence shell integrity, altering offspring survival and population dynamics. Similarly, female mysterysnails may reduce their overall body burden and the potential toxic effects of metals by offloading contaminants to offspring. A better understanding of maternal transfer in non-native mysterysnails is required to manage these non-native species effectively.