Department of Zoology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India.
Environ Monit Assess. 2023 Jul 24;195(8):985. doi: 10.1007/s10661-023-11530-0.
Planorbella trivolvis (ramshorn snail) is one of India's most extensively sold exotic aquarium pet snails. The unintentional or deliberate release of P. trivolvis may result in the colonisation and establishment as an invasive snail in freshwater ecosystems. However, the successful invasion of P. trivolvis will depend on several abiotic and biotic factors of the concerned freshwater ecosystem. We have assessed the possibility of overcoming the opposing factors in P. trivolvis invasion through laboratory-based experiments and examined the effects of household-derived pollutants on egg hatchability, adult survivability and fecundity, and temperature (15 to 35 °C) on growth, sexual maturity, and reproduction. Additionally, we have evaluated the potential of native predators as biotic resistance to invasion by prey-choice experiment. The results indicated that egg hatchability, adult survivability, and fecundity were reduced with increasing pollutant concentration. However, the same traits did not differ from a native freshwater snail, Indoplanorbis exustus. The fecundity of P. trivolvis increased with increasing body size, but no considerable differences at different temperature levels suggest a wide range of adaptation to temperature. Faster growth and the requirement of comparatively few days to attain sexual maturity were observed in the higher temperatures. The native predators, Glossiphonia weberi and Diplonychus rusticus, avoided P. trivolvis as prey over the alternative prey snails in most instances, suggesting the masking of biotic resistance against the colonisation. Our observations indicate that the chance dispersal of P. trivolvis from household or commercial aquaria may lead to a possible invasion of freshwater ecosystems under suitable conditions.
扁卷螺（Ramshorn 蜗牛）是印度最广泛销售的外来水族馆宠物蜗牛之一。扁卷螺的无意或故意释放可能导致其在淡水生态系统中定殖并成为入侵蜗牛。然而，扁卷螺的成功入侵将取决于相关淡水生态系统的几个非生物和生物因素。我们通过实验室实验评估了通过克服扁卷螺入侵的对立因素的可能性，并研究了家庭来源的污染物对卵孵化率、成虫存活率和繁殖力的影响，以及温度（15 至 35°C）对生长、性成熟和繁殖的影响。此外，我们还通过猎物选择实验评估了本地捕食者作为生物抵抗入侵的潜力。结果表明，随着污染物浓度的增加，卵孵化率、成虫存活率和繁殖力降低。然而，与本地淡水蜗牛 Indoplanorbis exustus 相比，这些特征并没有差异。扁卷螺的繁殖力随着体型的增大而增加，但不同温度水平之间没有明显差异，表明其对温度有广泛的适应性。在较高的温度下，生长速度更快，达到性成熟所需的天数也相对较少。本地捕食者 Glossiphonia weberi 和 Diplonychus rusticus 在大多数情况下避免将扁卷螺作为猎物，而选择替代猎物蜗牛，这表明对其定殖的生物抵抗能力被掩盖。我们的观察表明，扁卷螺从家庭或商业水族馆的偶然传播可能导致在适宜条件下淡水生态系统的潜在入侵。
