PT  - JOURNAL ARTICLE
AU  - Katja Leicht
AU  - Otto Seppälä
TI  - Direct and transgenerational effects of an experimental heat wave on early life stages in a freshwater snail
AID  - 10.1101/449777
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 449777
4099  - http://biorxiv.org/content/early/2018/10/22/449777.short
4100  - http://biorxiv.org/content/early/2018/10/22/449777.full
AB  - Global climate change imposes a serious threat to natural populations of many species. Estimates of the effects of climate change are, however, typically based only on its direct effects on organisms, completely neglecting the potential transgenerational effects. We investigated whether high temperature (an experimental heat wave) that reduces adult performance, affects offspring through maternal effects, which traits are affected, and how strong these effects are compared with direct effects of high temperature in the freshwater snail Lymnaea stagnalis. We examined the effect of maternal thermal environment (15°C versus 25°C) on per offspring investment (egg size), and the role of both maternal and offspring thermal environments on offspring performance (hatching success and developmental time of eggs, survival and size of hatched offspring after five weeks). Exposure of mothers to high temperature benefitted offspring at very early stages of their life cycles (hatching success, onset of hatching), but had negative effects at later stages (survival, size). Direct effects of high temperature on offspring were largely negative. Interestingly, the magnitude of transgenerational effects of high temperature on hatching success and survival were similar to its direct effects. This indicates that heat waves cannot only impact natural populations across generations, but that such effects can be equally strong to the direct effects of temperature. Our results highlight the importance of considering transgenerational effects of climate change when estimating its effects in the wild.