Thermal acclimation in the early life stages of Arctic char, Salvelinus alpinus

Author(s):  
A Shahsavarani ◽  
JS Ballantyne ◽  
PA Wright
2020 ◽  
Author(s):  
Samantha Victoria Beck ◽  
Katja Räsänen ◽  
Camille A. Leblanc ◽  
Skúli Skúlason ◽  
Zophonías O. Jónsson ◽  
...  

Abstract Background Organismal fitness can be determined at early life-stages, but phenotypic variation at these early life-stages has rarely been considered in studies on evolutionary diversification. The trophic apparatus has been shown to contribute to sympatric resource-mediated divergence in several taxa. However, processes underlying this diversification are poorly understood. Using a phenotypically variable morph of Icelandic Arctic charr (Salvelinus alpinus), we reared offspring from multiple families under standardized laboratory conditions and tested to what extent family (i.e. direct genetic and maternal effects) contributes to offspring morphology at hatching (H) and first feeding (FF). To understand the underlying mechanisms behind early life-stage variation in morphology, we examined how craniofacial shape varied according to family, egg size, offspring size and individual candidate genes related to craniofacial development. Finally, we assessed whether craniofacial shape and expression of genes related to craniofacial development covaried. Results We found effects of family for offspring craniofacial shape at both H and FF, whilst relative expression levels of Sgk1 (a gene involved in craniofacial shape divergence) correlated with craniofacial shape at FF. However, there were no evidence to suggest that mean egg size or individual offspring size influenced offspring morphology. Conclusions This study provides evidence for within population family effects for phenotypic variation in trophic morphology, indicating the potential for genetic and/or maternal effects to facilitate resource polymorphism.


2020 ◽  
Author(s):  
Samantha Victoria Beck ◽  
Katja Räsänen ◽  
Camille A. Leblanc ◽  
Skúli Skúlason ◽  
Zophonías O. Jónsson ◽  
...  

Abstract Background Organismal fitness can be determined at early life-stages, but phenotypic variation at early life-stages is rarely considered in studies on evolutionary diversification. The trophic apparatus has been shown to contribute to sympatric resource-mediated divergence in several taxa. However, processes underlying diversification in trophic traits are poorly understood. Using phenotypically variable Icelandic Arctic charr (Salvelinus alpinus), we reared offspring from multiple families under standardized laboratory conditions and tested to what extent family (i.e. direct genetic and maternal effects) contributes to offspring morphology at hatching (H) and first feeding (FF). To understand the underlying mechanisms behind early life-stage variation in morphology, we examined how craniofacial shape varied according to family, offspring size, egg size and candidate gene expression. Results Craniofacial shape (i.e. the Meckel’s cartilage and hyoid arch) was more variable between families than within families both across and within developmental stages. Differences in craniofacial morphology between developmental stages correlated with offspring size, whilst within developmental stages only shape at FF correlated with offspring size, as well as female mean egg size. Larger offspring and offspring from females with larger eggs consistently had a wider hyoid arch and contracted Meckel’s cartilage in comparison to smaller offspring.Conclusions This study provides evidence for family-level variation in early life-stage trophic morphology, indicating the potential for parental effects to facilitate resource polymorphism.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Samantha V. Beck ◽  
Katja Räsänen ◽  
Camille A. Leblanc ◽  
Skúli Skúlason ◽  
Zophonías O. Jónsson ◽  
...  

Abstract Background Organismal fitness can be determined at early life-stages, but phenotypic variation at early life-stages is rarely considered in studies on evolutionary diversification. The trophic apparatus has been shown to contribute to sympatric resource-mediated divergence in several taxa. However, processes underlying diversification in trophic traits are poorly understood. Using phenotypically variable Icelandic Arctic charr (Salvelinus alpinus), we reared offspring from multiple families under standardized laboratory conditions and tested to what extent family (i.e. direct genetic and maternal effects) contributes to offspring morphology at hatching (H) and first feeding (FF). To understand the underlying mechanisms behind early life-stage variation in morphology, we examined how craniofacial shape varied according to family, offspring size, egg size and candidate gene expression. Results Craniofacial shape (i.e. the Meckel’s cartilage and hyoid arch) was more variable between families than within families both across and within developmental stages. Differences in craniofacial morphology between developmental stages correlated with offspring size, whilst within developmental stages only shape at FF correlated with offspring size, as well as female mean egg size. Larger offspring and offspring from females with larger eggs consistently had a wider hyoid arch and contracted Meckel’s cartilage in comparison to smaller offspring. Conclusions This study provides evidence for family-level variation in early life-stage trophic morphology, indicating the potential for parental effects to facilitate resource polymorphism.


2019 ◽  
Vol 617-618 ◽  
pp. 67-79 ◽  
Author(s):  
GF de Carvalho-Souza ◽  
E González-Ortegón ◽  
F Baldó ◽  
C Vilas ◽  
P Drake ◽  
...  

2020 ◽  
Vol 3 (1) ◽  
pp. ACCEPTED
Author(s):  
Rho-Jeong Rae

This study investigated the boreal digging frog, Kaloula borealis, to determine the egg hatching period and whether the hatching period is affected by incubation temperature. The results of this study showed that all the eggs hatched within 48 h after spawning, with 28.1% (±10.8, n=52) hatching within 24 h and 99.9% (±0.23, n=49) within 48 h after spawning. A significant difference was noted in the mean hatching proportion of tadpoles at different water temperatures. The mean hatching rates between 15 and 24 h after spawning was higher at a water temperature of 21.1 (±0.2) °C than at 24.1 (±0.2) °C. These results suggest that incubation temperature affected the early life stages of the boreal digging frog, since they spawn in ponds or puddles that form during the rainy season.


2019 ◽  
Vol 73 (1) ◽  
pp. 163 ◽  
Author(s):  
Sergio A. Carrasco ◽  
Erika Meerhoff ◽  
Beatriz Yannicelly ◽  
Christian M. Ibáñez

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