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

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.

Life on the edge: survival and behavioural responses of freshwater gill‐breathing snails to declining water level and substratum drying

“…Finding a submerged area, more humid substratum or at least a patch of moist detritus is crucial for survival of snails stranded by a water‐level decrease (Strachan et al ., ; Verdonschot et al ., ). Similar movement response to air exposure has been observed in other gastropods, such as a pulmonate P. corneus (Poznańska et al ., ) and a gill‐breathing T. fuscatus (Egonmwan, ), as well as in other mobile invertebrates (Extence, ; Gough et al ., ; Poznańska et al ., ). However, active locomotion is a costly response (Denny, ; Ribi & Arter, ; Lauga & Hosoi, ).…”

“…Pulmonate snails are generally more tolerant to desiccation (Lodge et al ., ), which is probably related to their terrestrial origin (Aldridge, ; McMahon, ). Planorbarius corneus survived for more than 50 days of desiccation under a similar experimental protocol as that used in our study (Poznańska et al ., ). For tropical aestivating pulmonates, the survival time during air exposure can be extended up to 1–3 years (Richards, ; de Jong‐Brink, ; Parashar & Rao, ).…”

“…Others were more likely to preserve energetic resources for alternative defensive mechanisms and either stopped their movement in the middle zone of the long gradually drying tanks, even if a shelter had not been found, or did not move at all after a drastic, sudden decrease in the water level, when they had to crawl over the exposed bottom. A similar distance‐dependent migration from a gradually drying area was observed in a pulmonate snail of comparable size, P. corneus (Poznańska et al ., ). However, fewer individuals of this species moved on dry substratum after immediate dewatering compared with V. viviparus , contrasting with the notion that the potential for active movement in gill‐breathing snails is typically regarded as lower than that of pulmonates (Kappes & Haase, ).…”

The survival and behavioural responses of a near-shore chironomid and oligochaete to declining water levels and sandy substratum drying

“…In contrast, S. sticticus was able to survive high water loss from sediments, partly confirming our hypothesis assuming the resistance of near-shore invertebrates to drying with regard to this species. Nevertheless, S. sticticus also appears to be less adapted to emersion compared to other, more mobile invertebrates, such as gastropods and gammarids, which exhibit complex strategies consisting of several physiological and behavioural mechanisms (Poznańska et al, 2013(Poznańska et al, , 2015a. Therefore, predicted effects of climate change (e.g.…”

“…A physiological adaptation of certain insect species is a modification of their life cycle by accelerating their development to emerge as adults under drying conditions (Dettinger-Klemm, 2003;Tronstad et al, 2005;Verdonschot et al, 2015). Behavioural strategies include following the decreasing water level to reach submerged areas (horizontal migration) (Richardson et al, 2002;Poznańska et al, 2013Poznańska et al, , 2015a or burying into the moist substratum (vertical migration) (Imhof & Harrison, 1981;Stubbington et al, 2011;Poznańska et al, 2013Poznańska et al, , 2015aVerdonschot et al, 2015).…”