Influence of aestivation on the survival of Galba truncatula (Mollusca : Gasteropoda) populations according to altitude
作者:M. D. Goumghar、D. Rondelaud、G. Dreyfuss、M. Benlemlih
DOI:10.1051/limn/2001018
日期:2001.9
Field and laboratory studies on 11 populations of Galba truncatula were performed to determine the survival rate of snails after aestivation, to specify the range of their shell heights, and to establish the percentage of G. truncatula which burrowed in soil when summer drying occurred. These investigations were performed using six lowland populations living in central France (alt. 206-282 m) and five highland populations, located in the Massif central (alt. 806-900 m). The survival rate of G. truncatula after flooding dried soil with water was significantly higher in the highland than in the lowland populations (69.5-80.7 % in road ditches, for example, instead of 29.3-33.0%). The mean shell heights of surviving snails and the durations of snail re-activation in water did not show any significant variation, whatever the origin of snail population. The percentages of snails buried in drying soil were higher in the highland population (13.0 % and 15.0 % of juvenile snails, for example, instead of 4.0 % and 7.7 % in lowland snails). In the lowland population only young snails buried, whereas 5.8-8.3 % of adults in the highland population were partially burrowing. The local climate of the sites studied in the Massif central, and the ability of snails to burrow into the mud when stagnant water disappeared in July, might explain the higher survival rate during aestivation.
对11个Galba truncatula种群进行的野外和实验室研究旨在确定蜗牛在夏季休眠后的存活率,明确其壳高范围,并确定在夏季干旱发生时有多少G. truncatula会在土壤中埋藏。这些研究在法国中部的六个低地种群(海拔206-282米)和位于中央高地的五个高地种群(海拔806-900米)进行。G. truncatula在淹水干土后存活率在高地种群中显著高于低地种群(例如,在道路排水沟中为69.5-80.7%,而低地为29.3-33.0%)。存活蜗牛的平均壳高和在水中重新活化的持续时间无论蜗牛种群的来源如何均未显示显著差异。在干燥的土壤中埋藏的蜗牛比例在高地种群中更高(例如,青少年蜗牛埋藏率为13.0%和15.0%,而低地蜗牛为4.0%和7.7%)。在低地种群中只有年轻蜗牛会埋藏,而在高地种群中有5.8-8.3%的成年蜗牛是部分埋藏的。研究中高地的当地气候和蜗牛在静水消失后能够埋入泥土的能力,可能解释了其在夏季休眠期间更高的存活率。