Effect of substratum drying on the survival and migrations of a freshwater pulmonate snail Planorbarius corneus (Linnaeus, 1758)

Małgorzata Poznańska,Dorota Goleniewska,Tomasz Gulanicz,Tomasz Kakareko,Łukasz Jermacz,Jarosław Kobak

doi:10.1007/s10750-014-2130-z

Małgorzata Poznańska, Dorota Goleniewska + Show 4 more

Open Access

https://doi.org/10.1007/s10750-014-2130-z

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Abstract

Pulmonate snails inhabiting the near-shore zone of water bodies experience air exposure during water level fluctuations and some of them are known to survive long time in temporary basins. In laboratory, we investigated survival and behavioural defences (horizontal migrations and burrowing in substratum) of adult pulmonate snails Planorbarius corneus during substratum (sand and organic-rich) drying. We examined horizontal migrations at shorter and longer distances (24 and 48 cm), during gradual (8 days) or sudden water level drop rates. P. corneus was remarkably resistant to substratum drying, surviving 50 days on sand and more than 53 days on organic-rich bottom. The snails followed the retreating water level and grouped in the submerged parts of experimental tanks. This response was reduced on organic-rich bottom at a longer distance and with water level decreasing suddenly. Moreover, snails exposed to drying buried shallowly in both bottom types. Thus, P. corneus exhibited variable and efficient strategies enabling its survival during water level fluctuations, including active migrations following the retreating water level and burying in sediments.

Highlights

Snails, especially pulmonates, inhabit the near-shore zone of water bodies (e.g. Lodge, 1985; Underwood et al, 1992; Costil & Clement, 1996), which is strongly affected by water level fluctuations (e.g. Coops et al, 2003; Furey et al, 2004; Poznanska et al, 2009)
When the water level drops in summer, bottom dwellers such as freshwater snails are in danger of desiccation, anoxia and starvation, associated with air exposure (Ferreira et al, 2003; White et al, 2006; Akande et al, 2010)
At the end of the experiment, all snails exposed to desiccation on the sandy bottom died, Fig. 2 Survival (%) of control and air-exposed snails on A sandy and B organic-rich bottom as well as the water content (%) in sediments (Experiment 1)

Summary

Introduction

Especially pulmonates, inhabit the near-shore zone of water bodies (e.g. Lodge, 1985; Underwood et al, 1992; Costil & Clement, 1996), which is strongly affected by water level fluctuations (e.g. Coops et al, 2003; Furey et al, 2004; Poznanska et al, 2009). According to Ghiretti & Ghiretti-Magaldi (1975) and McMahon (1983), freshwater pulmonates show various degrees of readaptation to aquatic life, increasing from Lymnaeidae (with a typical lung), through Physidae, to the best adapted Planorbidae and Acroloxidae They can use dissolved oxygen through cutaneous respiration, and the two latter families have developed an accessory, neomorphic gill. A special physiological adaptation of some freshwater gastropods to prolonged air exposure is aestivation (Machin, 1975; Livingstone & de Zwaan, 1983) This is an aerobic dormancy exhibited in arid conditions including the lack of water and food as well as high temperatures (Nowakowska, 2011). We chose Planorbarius corneus Linnaeus, 1758 (Planorbidae) as a pulmonate snail model species, as it typically inhabits near-shore zones of water bodies subjected to temporary air exposures. We assumed that survival and burying behaviour would be better in organic-rich substratum, providing better protection against desiccation

Materials and methods

Results

Burying in the bottom

Conclusions