scholarly journals Does physiological tolerance to acute hypoxia and salinity change explain ecological niche in two intertidal crab species?

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Thomas R L Falconer ◽  
Islay D Marsden ◽  
Jonathan V Hill ◽  
Chris N Glover
Keyword(s):  
Ecological Niche ◽  
Acute Hypoxia ◽  
Cardiovascular Function ◽  
Environmental Stressors ◽  
Crab Species ◽  
Salinity Change ◽  
Physiological Tolerance ◽  
Intertidal Crab

Lay summary In response to acute salinity change or hypoxia, Hemigrapsus crenulatus exhibited better maintenance of osmoregulatory and cardiovascular function than Hemigrapsus sexdentatus. The greater physiological resilience of H. crenulatus is consistent with its habitation of an ecological niche that promotes greater exposure to environmental stressors than that of H. sexdentatus.

scholarly journals Multiple environmental stressors confine the ecological niche of the rotifer Cephalodella acidophila

2013 ◽  
Vol 58 (5) ◽  
pp. 1008-1015 ◽  
Author(s):  
THOMAS WEISSE ◽  
NICOLE LAUFENSTEIN ◽  
GUNTRAM WEITHOFF
Keyword(s):  
Ecological Niche ◽  
Environmental Stressors

scholarly journals Population growth rate and its determinants: an overview

2002 ◽  
Vol 357 (1425) ◽  
pp. 1153-1170 ◽  
Author(s):  
Richard M. Sibly ◽  
Jim Hone
Keyword(s):  
Growth Rate ◽  
Population Density ◽  
Population Growth ◽  
Population Ecology ◽  
Ecological Niche ◽  
Population Growth Rate ◽  
Population Regulation ◽  
Interference Competition ◽  
Environmental Stressors ◽  
Future Population

We argue that population growth rate is the key unifying variable linking the various facets of population ecology. The importance of population growth rate lies partly in its central role in forecasting future population trends; indeed if the form of density dependence were constant and known, then the future population dynamics could to some degree be predicted. We argue that population growth rate is also central to our understanding of environmental stress: environmental stressors should be defined as factors which when first applied to a population reduce population growth rate. The joint action of such stressors determines an organism's ecological niche, which should be defined as the set of environmental conditions where population growth rate is greater than zero (where population growth rate = r = log e ( N t +1 / N t )). While environmental stressors have negative effects on population growth rate, the same is true of population density, the case of negative linear effects corresponding to the well–known logistic equation. Following Sinclair, we recognize population regulation as occurring when population growth rate is negatively density dependent. Surprisingly, given its fundamental importance in population ecology, only 25 studies were discovered in the literature in which population growth rate has been plotted against population density. In 12 of these the effects of density were linear; in all but two of the remainder the relationship was concave viewed from above. Alternative approaches to establishing the determinants of population growth rate are reviewed, paying special attention to the demographic and mechanistic approaches. The effects of population density on population growth rate may act through their effects on food availability and associated effects on somatic growth, fecundity and survival, according to a 'numerical response', the evidence for which is briefly reviewed. Alternatively, there may be effects on population growth rate of population density in addition to those that arise through the partitioning of food between competitors; this is 'interference competition'. The distinction is illustrated using a replicated laboratory experiment on a marine copepod, Tisbe battagliae . Application of these approaches in conservation biology, ecotoxicology and human demography is briefly considered. We conclude that population regulation, density dependence, resource and interference competition, the effects of environmental stress and the form of the ecological niche, are all best defined and analysed in terms of population growth rate.

Refuge utilization and preferences between competing intertidal crab species

2009 ◽  
Vol 374 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Evie A. Wieters ◽  
Emilie Salles ◽  
Stella M. Januario ◽  
Sergio A. Navarrete
Keyword(s):  
Crab Species ◽  
Intertidal Crab

scholarly journals Rhythmic abdominal pumping movements in praying Mantises (Insecta: Mantodea)

2019 ◽  
Vol 51 (1) ◽  
pp. 29-40
Author(s):  
Frederick R. Prete ◽  
Aaron E. Schirmer ◽  
Salim Patel ◽  
Christina Carrion ◽  
Greg M. Prete ◽  
...  
Keyword(s):  
Ecological Niche ◽  
System Organization ◽  
Low Frequency ◽  
High Amplitude ◽  
Emergent Property ◽  
Environmental Stressors ◽  
Ecological Diversity ◽  
Analysis Software ◽  
Respiratory Behavior ◽  
Very High

We analyzed the rhythmic, cyclical dorsal-ventral abdominal pumping movements of nymphal and adult Hierodula patellifera (Audinet- Serville 1839), and adult Stagmomantis carolina (Johansson 1763), Tenodera sinensis (de Saussure 1871), Miomantis paykullii (Stål 1871), and Sphodromantis lineola (Burmeister 1838) using a combination of customized video analysis software and frame-by-frame video analyses. Despite the phylogenetic and ecological diversity of these species, we found fundamental similarities in the overall, intermittent patterns of their abdominal pumping movements. In adults of all species, intermittent bouts of abdominal pumping had median durations of 64-89 sec, and were separated by intervals with median durations of 10-25 sec. Bouts began with rhythmic upward abdominal deflections of progressively increasing amplitude and frequency which were superimposed on an overall, progressive abdominal elevation. Bouts ended with 1-4 very high amplitude, low frequency upward deflections after which the abdomen returned to its horizontal (resting) position. In H. patellifera, the overall adult pattern emerged gradually during larval development. Given the diversity of the species tested, our data suggest that intermittent abdominal pumping (which has been associated with respiratory behavior in insects) may be independent of ecological niche or acute environmental stressors in mantises. Instead, our data support the hypothesis that these apparently respiratory related, intermittent abdominal pumping movements are an emergent property of the mantis central nervous system organization.

Different ontogenetic trajectories of body colour, pattern and crypsis in two sympatric intertidal crab species

2020 ◽  
Vol 132 (1) ◽  
pp. 17-31
Author(s):  
Rafael C Duarte ◽  
Gustavo M Dias ◽  
Augusto A V Flores ◽  
Martin Stevens
Keyword(s):  
Habitat Use ◽  
Life Stage ◽  
Colour Pattern ◽  
Species Variation ◽  
Crab Species ◽  
Ontogenetic Changes ◽  
Heterogeneous Habitats ◽  
Intertidal Crab ◽  
Ontogenetic Trajectories ◽  
Mud Crabs

Abstract Animals frequently exhibit great variation in appearance, especially in heterogeneous habitats where individuals can be concealed differentially against backgrounds. Although background matching is a common anti-predator strategy, gaps exist in our understanding of within- and among-species variation. Specifically, the drivers of changes in appearance associated with habitat use and occurring through ontogeny are poorly understood. Using image analysis, we tested how individual appearance and camouflage in two intertidal crab species, the mud crab Panopeus americanus and the mottled crab Pachygrapsus transversus, relate to ontogeny and habitat use. We predicted that both species would change appearance with ontogeny, but that resident mud crabs would exhibit higher background similarity than generalist mottled crabs. Both species showed ontogenetic changes; the mud crabs became darker, whereas mottled crabs became more green. Small mud crabs were highly variable in colour and pattern, probably stemming from the use of camouflage in heterogeneous habitats during the most vulnerable life stage. Being habitat specialists, mud crabs were better concealed against all backgrounds than mottled crabs. Mottled crabs are motile and generalist, occupying macroalgae-covered rocks when adults, which explains why they are greener and why matches to specific habitats are less valuable. Differential habitat use in crabs can be associated with different coloration and camouflage strategies to avoid predation.

Local and meso-scale patterns of recruitment and abundance of two intertidal crab species that compete for refuges

2008 ◽  
Vol 155 (2) ◽  
pp. 223-232 ◽  
Author(s):  
Sergio A. Navarrete ◽  
Mirtala Parragué ◽  
Evie A. Wieters
Keyword(s):  
Crab Species ◽  
Intertidal Crab ◽  
Meso Scale
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