scholarly journals Characterizing phenotypic divergence using three-dimensional geometric morphometrics in four populations of threespine stickleback (Gasterosteus aculeatus; Pisces: Gasterosteidae) in Katmai National Park and Preserve, Alaska

2016 ◽  
Vol 94 (7) ◽  
pp. 463-472 ◽  
Author(s):  
A.E. Pistore ◽  
T.N. Barry ◽  
E. Bowles ◽  
R. Sharma ◽  
S.L. Vanderzwan ◽  
...  
Keyword(s):  
Geometric Morphometrics ◽  
National Park ◽  
Gasterosteus Aculeatus ◽  
Three Dimensional ◽  
Covariance Structure ◽  
Threespine Stickleback ◽  
Evolutionary Change ◽  
Ecological Processes ◽  
Vertebrate Model ◽  
Katmai National Park

The threespine stickleback (Gasterosteus aculeatus L., 1758) is a vertebrate model for the study of the relationship between phenotype and environment in facilitating rapid evolutionary change. Using four populations from a system of lakes in Katmai National Park and Preserve, Alaska, and microcomputed tomography and three-dimensional geometric morphometrics, we test the hypothesis that stickleback populations inhabiting freshwater environments display cranial phenotypes that are intermediate between the putative ancestral form and the low-plated freshwater populations that demonstrate substantial divergence toward new phenotypic optima. We further test the hypothesis that phenotypic covariance structure is disrupted in the context of such putatively recent adaptive events. We report significant phenotypic differences among all four populations that includes a component of sexual dimorphism. Furthermore, we show evidence of disrupted phenotypic covariance structure among these populations. Taken together, these findings indicate the importance of phenotypic quantification as a key step in elucidating both the ecological processes responsible for rapid adaptive radiations and the role of developmental mechanisms in biasing evolutionary change.

scholarly journals Diversity and sexual dimorphism in the head lateral line system in North Sea populations of threespine sticklebacks, Gasterosteus aculeatus (Teleostei: Gasterosteidae)

Zoomorphology ◽  
2020 ◽  
Author(s):  
Harald Ahnelt ◽  
David Ramler ◽  
Maria Ø. Madsen ◽  
Lasse F. Jensen ◽  
Sonja Windhager
Keyword(s):  
Sexual Dimorphism ◽  
North Sea ◽  
Lateral Line ◽  
Gasterosteus Aculeatus ◽  
Sensory System ◽  
Threespine Stickleback ◽  
Lateral Line System ◽  
Line System ◽  
Marine Population ◽  
Threespine Sticklebacks

AbstractThe mechanosensory lateral line of fishes is a flow sensing system and supports a number of behaviors, e.g. prey detection, schooling or position holding in water currents. Differences in the neuromast pattern of this sensory system reflect adaptation to divergent ecological constraints. The threespine stickleback, Gasterosteus aculeatus, is known for its ecological plasticity resulting in three major ecotypes, a marine type, a migrating anadromous type and a resident freshwater type. We provide the first comparative study of the pattern of the head lateral line system of North Sea populations representing these three ecotypes including a brackish spawning population. We found no distinct difference in the pattern of the head lateral line system between the three ecotypes but significant differences in neuromast numbers. The anadromous and the brackish populations had distinctly less neuromasts than their freshwater and marine conspecifics. This difference in neuromast number between marine and anadromous threespine stickleback points to differences in swimming behavior. We also found sexual dimorphism in neuromast number with males having more neuromasts than females in the anadromous, brackish and the freshwater populations. But no such dimorphism occurred in the marine population. Our results suggest that the head lateral line of the three ecotypes is under divergent hydrodynamic constraints. Additionally, sexual dimorphism points to divergent niche partitioning of males and females in the anadromous and freshwater but not in the marine populations. Our findings imply careful sampling as an important prerequisite to discern especially between anadromous and marine threespine sticklebacks.

Responses of threespine stickleback (Gasterosteus aculeatus, L) transcriptome to hypoxia

2011 ◽  
Vol 6 (4) ◽  
pp. 370-381 ◽  
Author(s):  
L. Leveelahti ◽  
P. Leskinen ◽  
E.H. Leder ◽  
W. Waser ◽  
M. Nikinmaa
Keyword(s):  
Gasterosteus Aculeatus ◽  
Threespine Stickleback

scholarly journals Heritability of DNA methylation in threespine stickleback (Gasterosteus aculeatus)

Genetics ◽  
2021 ◽  
Vol 217 (1) ◽  
Author(s):  
Juntao Hu ◽  
Sara J S Wuitchik ◽  
Tegan N Barry ◽  
Heather A Jamniczky ◽  
Sean M Rogers ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Genetic Architecture ◽  
Gasterosteus Aculeatus ◽  
Additive Genetic Variance ◽  
Natural Populations ◽  
Threespine Stickleback ◽  
Phenotypic Change ◽  
Cpg Sites ◽  
Cis And Trans ◽  
Methylation Variation

Abstract Epigenetic mechanisms underlying phenotypic change are hypothesized to contribute to population persistence and adaptation in the face of environmental change. To date, few studies have explored the heritability of intergenerationally stable methylation levels in natural populations, and little is known about the relative contribution of cis- and trans-regulatory changes to methylation variation. Here, we explore the heritability of DNA methylation, and conduct methylation quantitative trait loci (meQTLs) analysis to investigate the genetic architecture underlying methylation variation between marine and freshwater ecotypes of threespine stickleback (Gasterosteus aculeatus). We quantitatively measured genome-wide DNA methylation in fin tissue using reduced representation bisulfite sequencing of F1 and F2 crosses, and their marine and freshwater source populations. We identified cytosines (CpG sites) that exhibited stable methylation levels across generations. We found that additive genetic variance explained an average of 24–35% of the methylation variance, with a number of CpG sites possibly autonomous from genetic control. We also detected both cis- and trans-meQTLs, with only trans-meQTLs overlapping with previously identified genomic regions of high differentiation between marine and freshwater ecotypes. Finally, we identified the genetic architecture underlying two key CpG sites that were differentially methylated between ecotypes. These findings demonstrate a potential role for DNA methylation in facilitating adaptation to divergent environments and improve our understanding of the heritable basis of population epigenomic variation.

scholarly journals Long-term UVB exposure promotes predator-inspection behaviour in a fish

2017 ◽  
Vol 13 (12) ◽  
pp. 20170497 ◽  
Author(s):  
Simon Vitt ◽  
Janina E. Zierul ◽  
Theo C. M. Bakker ◽  
Ingolf P. Rick
Keyword(s):  
Gasterosteus Aculeatus ◽  
Stratospheric Ozone ◽  
Ultraviolet B ◽  
Antipredator Behaviour ◽  
Uvb Radiation ◽  
Ecological Processes ◽  
Predator Prey ◽  
Natural Sunlight ◽  
Predator Inspection

Ultraviolet-B radiation (UVB) reaching the earth's surface has increased due to human-caused stratospheric ozone depletion. Whereas the harmful effects of UVB on aquatic organisms are well studied at the molecular and cellular level, recent studies have also begun to address behavioural changes caused by sublethal amounts of UVB. However, the behavioural consequences of long-term exposure to ecologically relevant UVB levels over several life stages are virtually unknown, particularly with regard to predator–prey behaviour. We found increased predator-inspection behaviour together with a smaller body length in three-spined sticklebacks ( Gasterosteus aculeatus ) after fish were exposed for about seven months to natural sunlight conditions with enhanced UVB, compared with full siblings exposed to natural sunlight only. The observed change in antipredator behaviour may reflect a direct behavioural response mediated through UVB-induced oxidative stress during development. Alternatively, the smaller body size in UVB-exposed fish may result in an increased inspection effort allowing them to spend more time foraging. Our findings suggest that, within the scope of environmental change, UVB radiation constitutes an important stress factor by eliciting behavioural responses that influence crucial ecological processes, such as predator–prey interactions.

Host mortality and variability in epizootics of Schistocephalus solidus infecting the threespine stickleback, Gasterosteus aculeatus

Parasitology ◽  
2010 ◽  
Vol 137 (11) ◽  
pp. 1681-1686 ◽  
Author(s):  
D. C. HEINS ◽  
E. L. BIRDEN ◽  
J. A. BAKER
Keyword(s):  
Gasterosteus Aculeatus ◽  
Infected Fish ◽  
Threespine Stickleback ◽  
Intensity Of Infection ◽  
Host Fish ◽  
Schistocephalus Solidus ◽  
Second Intermediate Host ◽  
Host Mortality ◽  
Abiotic And Biotic Factors ◽  
Host Behaviour

SUMMARYAn analysis of the metrics of Schistocephalus solidus infection of the threespine stickleback, Gasterosteus aculeatus, in Walby Lake, Alaska, showed that an epizootic ended between 1996 and 1998 and another occurred between 1998 and 2003. The end of the first epizootic was associated with a crash in population size of the stickleback, which serves as the second intermediate host. The likely cause of the end of that epizootic is mass mortality of host fish over winter in 1996–1997. The deleterious impact of the parasite on host reproduction and increased host predation associated with parasitic manipulation of host behaviour and morphology to facilitate transmission might also have played a role, along with unknown environmental factors acting on heavily infected fish or fish in poor condition. The second epizootic was linked to relatively high levels of prevalence and mean intensity of infection, but parasite:host mass ratios were quite low at the peak and there were no apparent mass deaths of the host. A number of abiotic and biotic factors are likely to interact to contribute to the occurrence of epizootics in S. solidus, which appear to be unstable and variable. Epizootics appear to depend on particular and, at times, rare sets of circumstances.

State-shifts of lion prey selection in the Kruger National Park

2017 ◽  
Vol 44 (1) ◽  
pp. 28 ◽  
Author(s):  
N. T. Maruping-Mzileni ◽  
P. J. Funston ◽  
S. M. Ferreira
Keyword(s):  
National Park ◽  
Prey Selection ◽  
Management Strategies ◽  
Stable State ◽  
Kruger National Park ◽  
Ecological Processes ◽  
Policy Makers ◽  
Predator Prey ◽  
Key Indicator ◽  
Management Interventions

Aims Indicators of pending state-shifts carry value for policy makers. Predator–prey relations reflect key ecological processes that shape ecosystems. Variance in predator–prey relations may serve as a key indicator of future state-shifts. Methods Lion (Panthera leo) diet in the Kruger National Park was evaluated as such an indicator. Over the three-decade time span reviewed, variance in diet in relation to rainfall, prey abundance, management strategies and disease emergence were reviewed. Key results Rainfall patterns, both seasonal and cyclical, were identified as key drivers of predator–prey selection. However, the intensity of management in the form of artificial waterpoints overrode and confounded natural process. The results suggest that savanna systems are stable and punctuated by climatic events in the form of extreme above-average rainfall that temporarily destabilises the system. However, droughts are a cyclical part of the savanna system. Conclusion Lion prey selection did fluctuate with changing environmental conditions. Abrupt state shifts did occur; however, the ecosystem returned to a stable state. Implications State shifts in ecosystems pose key challenges to conservation managers. State shifts appear to be primarily associated with management interventions and environmental factors.

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