Embryonic water uptake during pregnancy is stage- and fecundity-dependent in the snake Vipera aspis.

摘要: Abstract Water is a crucial resource that can profoundly impact the biology of terrestrial organisms. Early life stages are particularly sensitive to hydric constraints because water uptake an important component embryonic development. While amniotic eggs constitute key innovation life, many vertebrates viviparous wherein mother must be source for her developing embryos. Since most squamates lecithotrophic (i.e., energy supplied offspring as yolk deposited into pre-ovulated follicles), predominant allocated from during Contrary stored (e.g., fat reserves), typically cannot acquired in advance. Therefore, embryos' need impose significant on pregnant female. We detailed flux pregnancy snake, aspic viper ( Vipera aspis ). found occurred mostly second half pregnancy—a period dominated by somatic growth. also that, somewhat unexpectedly, changes female plasma osmolality were negatively related fecundity. This latter result suggests consumption especially large litter sizes, and thus may suggest sensitivity reproductive females environmental availability.