scholarly journals Direct and transgenerational effects of an experimental heat wave on early life stages in a freshwater snail

2018 ◽  
Author(s):  
Katja Leicht ◽  
Otto Seppälä

AbstractGlobal climate change imposes a serious threat to natural populations of many species. Estimates of the effects of climate change-mediated environmental stresses are, however, often based only on their direct effects on organisms, and neglect the potential transgenerational effects. We investigated whether high temperature (i.e. an experimental heat wave) that is known to reduce performance of adult Lymnaea stagnalis snails affects their offspring through maternal effects. Specifically, we tested whether eggs and hatched juveniles are affected by maternal thermal environment, and how strong these effects are compared with direct effects of temperature on offspring. 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 (15°C versus 25°C) on hatching success and developmental time of eggs, offspring survival after hatching, and hatchling size at the age of five weeks. Exposure of mothers to high temperature increased hatching success of eggs, and also made the onset of hatching earlier. However, high maternal temperature reduced the survival and the final size of hatched juveniles. Direct effects of high temperature on offspring survival were negative (both eggs and hatchlings), but increased the developmental rate and growth of those eggs and hatchlings that survived. Interestingly, the magnitude of transgenerational effects of high temperature on hatching success of eggs and hatchling survival were similar to its direct effects. This indicates that heat waves can affect natural populations through transgenerational effects, and that the magnitude of such effects can be equally strong to the direct effects of temperature, although this depends on the trait considered. Our results highlight the importance of considering transgenerational effects of climate warming when estimating its effects in the wild.

2020 ◽  
Author(s):  
Aaron A. Comeault ◽  
Daniel R. Matute

AbstractChanges in temperature associated with climate change can alter species’ distributions, drive adaptive evolution, and, in some cases, cause extinction. Research has tended to focus on the direct effects of temperature, but changes in temperature can also have indirect effects on populations and species. Here we test whether temperature can indirectly affect the fitness of Drosophila santomea and D. yakuba by altering interspecific competitive outcomes. We show that, when raised in isolation, both D. santomea and D. yakuba show maximal performance at temperatures near 22°C. However, when raised together, D. santomea outcompetes D. yakuba at a lower temperature (18°C), while D. yakuba outcompetes D. santomea at a higher temperature (25°C). We then use a ‘coexistence’ experiment to show that D. santomea is rapidly (within 8 generations) extirpated when maintained with D. yakuba at 25°C. By contrast, D. santomea remains as (or more) abundant than D. yakuba over the course of ~10 generations when maintained at 18°C. Our results provide an example of how the thermal environment can indirectly affect interspecific competitive outcomes and suggest that changes in the competitive advantage of species can lead to some species becoming more prone to extinction by competitive exclusion.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Noémie Deldicq ◽  
Dewi Langlet ◽  
Camille Delaeter ◽  
Grégory Beaugrand ◽  
Laurent Seuront ◽  
...  

AbstractHeatwaves have increased in intensity, duration and frequency over the last decades due to climate change. Intertidal species, living in a highly variable environment, are likely to be exposed to such heatwaves since they can be emerged for more than 6 h during a tidal cycle. Little is known, however, on how temperature affects species traits (e.g. locomotion and behaviour) of slow-moving organisms such as benthic foraminifera (single-celled protists), which abound in marine sediments. Here, we examine how temperature influences motion-behaviour and metabolic traits of the dominant temperate foraminifera Haynesina germanica by exposing individuals to usual (6, 12, 18, 24, 30 °C) and extreme (high; i.e. 32, 34, 36 °C) temperature regimes. Our results show that individuals reduced their activity by up to 80% under high temperature regimes whereas they remained active under the temperatures they usually experience in the field. When exposed to a hyper-thermic stress (i.e. 36 °C), all individuals remained burrowed and the photosynthetic activity of their sequestered chloroplasts significantly decreased. Recovery experiments subsequently revealed that individuals initially exposed to a high thermal regime partially recovered when the hyper-thermic stress ceased. H. germanica contribution to surface sediment reworking substantially diminished from 10 mm3 indiv−1 day−1 (usual temperature) to 0 mm3 indiv−1 day−1 when individuals were exposed to high temperature regimes (i.e. above 32 °C). Given their role in sediment reworking and organic matter remineralisation, our results suggest that heatwaves may have profound long-lasting effects on the functioning of intertidal muddy ecosystems and some key biogeochemical cycles.


Ecology ◽  
2021 ◽  
Author(s):  
Oliver J. Wilmot ◽  
James M. Hood ◽  
Alexander D. Huryn ◽  
Jonathan P. Benstead

Parasitology ◽  
2015 ◽  
Vol 142 (10) ◽  
pp. 1290-1296 ◽  
Author(s):  
SIRPA KAUNISTO ◽  
LAURA HÄRKÖNEN ◽  
MARKUS J. RANTALA ◽  
RAINE KORTET

SUMMARYImmunity of parasites has been studied amazingly little, in spite of the fact that parasitic organisms, especially the arthropod parasites, need immunity to survive their own infections to successfully complete life cycles. Long-term effects of challenging environmental temperatures on immunity have remained unstudied in insects and parasites. Our study species, the deer ked (Lipoptena cervi; Linnaeus 1758), is an invasive, blood-feeding parasitic fly of cervids. Here, it was studied whether thermal stress during the pupal diapause stage could modify adult immunity (encapsulation capacity) in L. cervi. The effect of either a low temperature or high temperature peak, experienced during winter dormancy, on encapsulation response of active adult was tested. It was found that low temperature exposure during diapause, as long as the temperature is not too harsh, had a favourable effect on adult immunity. An abnormal, high temperature peak during pupal winter diapause significantly deteriorated the encapsulation capacity of emerged adults. The frequency and intensity of extreme weather events such as high temperature fluctuations are likely to increase with climate change. Thus, the climate change might have previously unknown influence on host-ectoparasite interactions, by affecting ectoparasite's immune defence and survival.


2021 ◽  
Vol 13 (7) ◽  
pp. 3614
Author(s):  
Zeyad Amin Al-Absi ◽  
Mohd Isa Mohd Hafizal ◽  
Mazran Ismail ◽  
Azhar Ghazali

Building sector is associated with high energy consumption and greenhouse gas emissions, which contribute to climate change. Sustainable development emphasizes any actions to reduce climate change and its effect. In Malaysia, half of the energy utilized in buildings goes towards building cooling. Thermal comfort studies and adaptive thermal comfort models reflect the high comfort temperatures for Malaysians in naturally conditioned buildings, which make it possible to tackle the difference between buildings’ indoor temperature and the required comfort temperature by using proper passive measures. This study investigates the effectiveness of building’s retrofitting with phase change materials (PCMs) as a passive cooling technology to improve the indoor thermal environment for more comfortable conditions. PCM sheets were numerically investigated below the internal finishing of the walls. The investigation involved an optimization study for the PCMs transition temperatures and quantities. The results showed significant improvement in the indoor thermal environment, especially when using lower transition temperatures and higher quantities of PCMs. Therefore, the monthly thermal discomfort time has decreased completely, while the thermal comfort time has increased to as high as 98%. The PCM was effective year-round and the optimum performance for the investigated conditions was achieved when using 18mm layer of PCM27-26.


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