Thermal Tolerance and Evaporative Water Loss of the Mangrove Prosobranch Tympanotonus fuscatus var. radula L. (Cerithiacea: Potamididae)

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

“…Survival times obtained in our studies for larger snails were relatively high for gill‐breathing snails. Slightly longer survival (four weeks) was noted by Egonmwan () for a gill‐breathing, bigger, tropical, mangrove periwinkle Tympanotonus fuscatus var. radula .…”

“…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, ).…”

“…Burrowing of snails and other molluscs is usually shallow, up to 3 cm (Seuffert, Burela & Martín, ; Archambault, Cope & Kwak, , ), although some species have been reported to burrow at depths as great as 7 cm (pulmonate snails; Cheatum, ) or even 20 cm (infaunal unionid mussels; Schwalb & Pusch, ). Burrowing as a reaction to substratum drying was noted in a gill‐breathing snail T. fuscatus in the field (Egonmwan, ) as well as in a pulmonate P. corneus in the laboratory (Poznańska et al ., ). Burrowing into the bottom sediments, which are more humid and cooler, increases the survival of gastropods and allows them to wait for better environmental conditions (McMahon, ; Alonso & Castro‐Díez, ; Kappes & Haase, ).…”

“…Aestivation, which involves reduced metabolic demands, along with physical isolation from the environment to cope with adverse environmental conditions (Aldridge, 1983;McMahon, 1990), has been observed in tropical amphibious ampullariid snails (Little, 1968;Scholnick, Snyder & Spell, 1994). Desiccation resistance of gill-breathing snails in which aestivation has not been confirmed has often been studied by allowing snails to dry on blotting paper without any substratum (Skoog, 1976;Facon et al, 2004;Egonmwan, 2007;Wood et al, 2011;Collas et al, 2014). This distinctly shortened their survival, because the conditions changed rapidly and the snails had no time to acclimate, whereas it is known that invertebrates may require long lead times to prepare for drying (Wiggins, 1973).…”

Diesel exposure of <i>Tympanotonus fuscatus</i> and its effects on enzyme activity

“…Despite high reportage of oil spills and illegal oil activities in the Nigerian coastal water, there is scarcity of report or documentation on the effect of crude oil or its fractions on tissue biochemistry of an important brackish species Tympanotonus fuscatus, despite the efforts towards heavy metals accumulation and total hydrocarbon content and mortality of this species in post spill incidence (Daka et al, 2006;Ideriah et al, 2006;Egonmwan, 2007;Renner et al, 2008;Benson and Essien, 2009;Ewa-Oboho and Otogo, 2009;). This study investigates changes in the enzymes of the periwinkle (Tympanotonus fuscatus) exposed to diesel a refined product of crude oil.…”