scholarly journals Negative body size‐dependent resource allocation underlies conspicuous sexual ornaments in a territorial damselfly

2021 ◽  
Author(s):  
Mingzi Xu ◽  
Ola M. Fincke
Keyword(s):  
Resource Allocation ◽  
Body Size ◽  
Sexual Ornaments ◽  
Size Dependent

Body size-dependent Cd accumulation in the zebra mussel Dreissena polymorpha from different routes

Chemosphere ◽  
2017 ◽  
Vol 168 ◽  
pp. 825-831 ◽  
Author(s):  
Wen-Li Tang ◽  
Douglas Evans ◽  
Lisa Kraemer ◽  
Huan Zhong
Keyword(s):  
Body Size ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Cd Accumulation ◽  
Size Dependent

An ecological explanation for hyperallometric scaling of reproduction

2021 ◽  
Author(s):  
Tomos Potter ◽  
Anja Felmy
Keyword(s):  
Body Size ◽  
Reproductive Output ◽  
Resource Competition ◽  
Natural Populations ◽  
Scaling Exponent ◽  
Wild Populations ◽  
Wet Season ◽  
Size Dependent ◽  
In The Wild ◽  
The Relationship

AbstractIn wild populations, large individuals have disproportionately higher reproductive output than smaller individuals. We suggest an ecological explanation for this observation: asymmetry within populations in rates of resource assimilation, where greater assimilation causes both increased reproduction and body size. We assessed how the relationship between size and reproduction differs between wild and lab-reared Trinidadian guppies. We show that (i) reproduction increased disproportionately with body size in the wild but not in the lab, where effects of resource competition were eliminated; (ii) in the wild, the scaling exponent was greatest during the wet season, when resource competition is strongest; and (iii) detection of hyperallometric scaling of reproduction is inevitable if individual differences in assimilation are ignored. We propose that variation among individuals in assimilation – caused by size-dependent resource competition, niche expansion, and chance – can explain patterns of hyperallometric scaling of reproduction in natural populations.

Size-dependent seasonal activity for males of the dung beetle Copris acutidens (Coleoptera: Scarabaeidae)

2019 ◽  
Vol 151 (6) ◽  
pp. 757-767 ◽  
Author(s):  
Mayumi Akamine
Keyword(s):  
Body Size ◽  
Sex Ratio ◽  
Dung Beetle ◽  
Threshold Value ◽  
Reproductive Period ◽  
Seasonal Activity ◽  
Size Dependent ◽  
Horn Length ◽  
Female Bias ◽  
Early Activity

AbstractThis study aimed to determine differences in activities between two male morphs of the dung beetle Copris acutidens Motschulsky (Coleoptera: Scarabaeidae) during the reproductive period and to examine the size distribution of reproductive males that stayed in nests. The activities of two male morphs distinguished by a threshold value of body size were compared with those by horn length. Regardless of body size or horn length, earlier activity of minor males was observed during the reproductive period. The sex ratio showed the greatest female bias when minor males were the more abundant than major males, indicating that minor males were the most active when competition was the weakest and these could avoid direct combat with major males. In morphs distinguished by horn length, more major males than minor males stayed in nests with females although the major males became the most active from the middle of the reproductive period. Thus, longer horns may directly confer a competitive advantage to males, enabling them to stay in nests with females, whereas early activity of minor males does not always indicate the effect of horn length directly. Therefore, this behaviour may occur regardless of whether the morphs differ in body size or horn length.

scholarly journals Perch Selection by Three Cooccurring Species ofCelithemis(Odonata: Libellulidae): Testing for a Competitive Hierarchy among Similar Species

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Wade B. Worthen ◽  
Parker H. Morrow
Keyword(s):  
Body Size ◽  
Niche Partitioning ◽  
Open Water ◽  
The Other ◽  
Similar Species ◽  
Male Body ◽  
Size Dependent ◽  
Anatomical Characters ◽  
Relative Abundances ◽  
Imagej Software

In many communities of perching dragonflies (Odonata: Libellulidae), a size-dependent competitive hierarchy creates a positive relationship between male body size and perch height. We tested for this pattern among three similar-sized species:Celithemis elisa,C. fasciata, andC. ornata.Males were caught and photographed from May to July 2015 at Ashmore Heritage Preserve, Greenville County, SC, USA, and perch heights and perch distance to open water were measured. Five indices of body size were measured with ImageJ software: abdomen length, forewing length, hindwing length, area of forewing, and area of hindwing.Celithemis fasciatawas significantly larger than the other two species for all five anatomical characters and used perches that were significantly taller and closer to open water than the other species, though these differences changed over the summer. Aggressive interactions between and within species were tallied and compared to expected distributions based on mean relative abundances derived from hourly abundance counts. Patterns of interspecific aggression were also consistent with a size-dependent hierarchy: the largeC. fasciatawas attacked less frequently, and the smallC. ornatamore frequently, than predicted by their relative abundances. We conclude that even small differences in body size may contribute to niche partitioning in perch selection.

Body-size-dependent Iodine-131 S values

2020 ◽  
Vol 40 (4) ◽  
pp. 1311-1320
Author(s):  
Yeon Soo Yeom ◽  
Keith Griffin ◽  
Bangho Shin ◽  
Chansoo Choi ◽  
Haegin Han ◽  
...  
Keyword(s):  
Body Size ◽  
Size Dependent ◽  
Iodine 131

A Novel Approach to Scaling Age-, Sex-, and Body Size-Dependent Thoracic Responses using Structural Properties of Human Ribs

2020 ◽  
Author(s):  
Yun-Seok Kang ◽  
John H. Bolte IV ◽  
Jason Stammen ◽  
Kevin Moorhouse ◽  
Amanda M. Agnew
Keyword(s):  
Body Size ◽  
Structural Properties ◽  
Size Dependent ◽  
Novel Approach

scholarly journals The evolution of genetic and conditional alternative reproductive tactics

2016 ◽  
Vol 283 (1825) ◽  
pp. 20152945 ◽  
Author(s):  
Leif Engqvist ◽  
Michael Taborsky
Keyword(s):  
Body Size ◽  
Size Variation ◽  
Alternative Reproductive Tactics ◽  
Disruptive Selection ◽  
Relevant Parameter ◽  
Reproductive Tactics ◽  
Adaptive Diversification ◽  
Size Dependent ◽  
Mortality Causes ◽  
Genetically Determined

Frequency-dependent selection may drive adaptive diversification within species. It is yet unclear why the occurrence of alternative reproductive tactics (ARTs) is highly divergent between major animal taxa. Here we aim to clarify the environmental and social conditions favouring the evolution of intra-population variance of male reproductive phenotypes. Our results suggest that genetically determined ARTs that are fixed for life evolve when there is strong selection on body size due to size-dependent competitiveness, in combination with environmental factors reducing size benefits. The latter may result from growth costs or, more generally, from age-dependent but size-independent mortality causes. This generates disruptive selection on growth trajectories underlying tactic choice. In many parameter settings, the model also predicts ARTs to evolve that are flexible and responsive to current conditions. Interestingly, the conditions favouring the evolution of flexible tactics diverge considerably from those favouring genetic variability. Nevertheless, in a restricted but relevant parameter space, our model predicts the simultaneous emergence and maintenance of a mixture of multiple tactics, both genetically and conditionally determined. Important conditions for the emergence of ARTs include size variation of competitors, which is inherently greater in species with indeterminate growth than in taxa reproducing only after reaching their terminal body size. This is probably the reason why ARTs are more common in fishes than in other major taxa.

Phosphorus Fluxes in Limnetic Cladocerans: Coupling of Allometry and Compartmental Analysis

1994 ◽  
Vol 51 (5) ◽  
pp. 1055-1064 ◽  
Author(s):  
Yuan Hua Wen ◽  
Alain Vézina ◽  
Robert Henry Peters
Keyword(s):  
Body Weight ◽  
Steady State ◽  
Body Size ◽  
Time Course ◽  
Compartmental Analysis ◽  
Compartment Model ◽  
Size Dependent ◽  
Two Compartment Model ◽  
Metabolic Activities ◽  
Total P

A size-dependent two-compartment model was developed for estimation of 32P turnover and fluxes by limnetic cladocerans in steady state. After feeding on radioactively labelled food, uniformly labelled animals were fed unlabelled cells and the time course of release of tracer followed. Rates of turnover and size-specific fluxes were subsequently fitted to a two-compartment model. The model predicted that steady-state turnover and size-specific fluxes for 32P excretion declined with body weight and that the exponent of weight did not significantly differ from −0.25, suggesting the relationships between total P turnover or flux rates and body size in cladocerans follow the same allometry observed for other organisms and other metabolic activities. However, rate constants for intercompartmental exchanges declined faster than weight−0.25, indicating that their turnover and flux declined much faster with increasing body size than would be expected from general allometry. Size-specific ingestion and assimilation rates of 32P by cladocerans decreased with increasing body size with a slope of the allometric function similar to −0.25.

Two Processes Regulating Trophic Energy Flow in Pelagic and Terrestrial Ecosystems: Trophic Efficiency and Body Size–Dependent Biomass Production: (A Reply to Giacomini)

2018 ◽  
Vol 191 (3) ◽  
pp. 364-367
Author(s):  
Richard McGarvey ◽  
Natalie Dowling ◽  
Joel E. Cohen
Keyword(s):  
Body Size ◽  
Biomass Production ◽  
Energy Flow ◽  
Terrestrial Ecosystems ◽  
Size Dependent
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