scholarly journals Phenology of hatching, emergence, and end-of-season body size in young-of-year coho salmon in thermally contrasting streams draining the Copper River Delta, Alaska

2019 ◽  
Vol 76 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Emily Y. Campbell ◽  
Jason B. Dunham ◽  
Gordon H. Reeves ◽  
Steve M. Wondzell
Keyword(s):  
Body Size ◽  
Environmental Variability ◽  
Coho Salmon ◽  
Growing Season ◽  
Early Life History ◽  
Growth And Survival ◽  
Individual Fitness ◽  
Marked Variability ◽  
Thermal Regimes ◽  
Body Sizes

Phenology can be linked to individual fitness, particularly in strongly seasonal environments where the timing of events has important consequences for growth, condition, and survival. We studied the phenology of coho salmon (Oncorhynchus kisutch) hatching and emergence in streams with contrasting thermal variability but in close geographic proximity. Following emergence, we tracked body sizes of cohorts of young-of-year fish until the end of the growing season. Hatch and emergence occurred at the same time among streams with marked variability in thermal regimes. We demonstrate that this can be explained in part by the thermal units accumulated during embryo development. At the end of the first growing season, there were some differences in body size, but overall fish size was similar among streams despite strong differences in thermal regimes. Collectively, these results provide novel insights into the interactions between environmental variability and the early life-history stages of coho salmon, furthering our understanding of the consequences of phenology on growth and survival for individuals within the critical first summer of life.

Relationship of larval density and heterozygosity to growth and survival of juvenile marbled salamanders (Ambystoma opacum)

1996 ◽  
Vol 74 (6) ◽  
pp. 1122-1129 ◽  
Author(s):  
Anne C. Chazal ◽  
John D. Krenz ◽  
David E. Scott
Keyword(s):  
Body Size ◽  
Larval Density ◽  
Larval Growth ◽  
Adult Survival ◽  
Growth And Survival ◽  
Ambystoma Opacum ◽  
Size At Metamorphosis ◽  
Body Sizes ◽  
Marbled Salamander ◽  
Relationship Of

Intraspecific competition and enzyme variability have been observed to influence the bioenergetics of many organisms. In amphibians, larval growth affects body size at metamorphosis, which in turn can lead to differences in adult survival and fecundity. We manipulated larval density in a population of the marbled salamander, Ambystoma opacum, and measured body size and enzyme variability in surviving newly metamorphosed juveniles. Crowded larval conditions resulted in lower survival and smaller body sizes at metamorphosis. Multilocus heterozygosity showed no relation to body size at high larval densities; however, at low larval densities relatively homozygous animals were larger. There was a significant interaction between heterozygosity and larval density in their effects on larval traits. Competition had a greater effect on body size at metamorphosis than did heterozygosity. Survival may be enhanced by heterozygosity but in a manner unrelated to body size.

scholarly journals Sex-specific covariance between metabolic rate, behaviour and morphology in the ground beetle Carabus hortensis

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12455
Author(s):  
Elisabeth Yarwood ◽  
Claudia Drees ◽  
Jeremy E. Niven ◽  
Wiebke Schuett
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Body Mass ◽  
Ground Beetle ◽  
Exploratory Behaviour ◽  
Temperature Dependent ◽  
Sexual Dimorphisms ◽  
Individual Fitness ◽  
Body Sizes ◽  
Mass Dependent

Background Individuals within the same species often differ in their metabolic rates, which may covary with behavioural traits (such as exploration), that are consistent across time and/or contexts, and morphological traits. Yet, despite the frequent occurrence of sexual dimorphisms in morphology and behaviour, few studies have assessed whether and how sexes differ in metabolic trait covariances. Methods We investigated sex-specific relationships among resting or active metabolic rate (RMR and AMR, respectively) with exploratory behaviour, measured independently of metabolic rate in a novel environment, body size and body mass, in Carabus hortensis ground beetles. Results RMR, AMR and exploratory behaviour were repeatable among individuals across time, except for male RMR which was unrepeatable. Female RMR neither correlated with exploratory behaviour nor body size/body mass. In contrast, AMR was correlated with both body size and exploratory behaviour. Males with larger body sizes had higher AMR, whereas females with larger body sizes had lower AMR. Both male and female AMR were significantly related to exploratory behaviour, though the relationships between AMR and exploration were body mass-dependent in males and temperature-dependent in females. Discussion Differences between sexes exist in the covariances between metabolic rate, body size and exploratory behaviour. This suggests that selection acts differently on males and females to produce these trait covariances with potentially important consequences for individual fitness.

scholarly journals Contrasting size and fate of juvenile crown-of-thorns starfish linked to ontogenetic diet shifts

2020 ◽  
Vol 287 (1931) ◽  
pp. 20201052
Author(s):  
Jennifer C. Wilmes ◽  
Andrew S. Hoey ◽  
Morgan S. Pratchett
Keyword(s):  
Population Dynamics ◽  
Body Size ◽  
Coralline Algae ◽  
Phenotypic Traits ◽  
Diet Shift ◽  
Growth And Survival ◽  
Ontogenetic Diet Shift ◽  
Individual Fitness ◽  
Ontogenetic Diet Shifts ◽  
Diet Shifts

Population dynamics of organisms are shaped by the variation in phenotypic traits, often expressed even among individuals from the same cohort. For example, individual variation in the timing of ontogenetic shifts in diet and/or habitat greatly influences subsequent growth and survival of some organisms, with critical effects on population dynamics. Few studies of natural systems have, however, demonstrated that marked phenotypic variation in growth rates or body size among individuals within a modelled cohort is linked to dietary shifts and food availability. Population irruptions of the crown-of-thorns starfish are one of the foremost contributors to the global degradation of coral reefs, but causes of irruptions have been debated for decades. Here we demonstrate, based on extensive field sampling of juvenile starfish ( n = 3532), that marked variation in body size among juvenile starfish is linked to an ontogenetic diet shift from coralline algae to coral. This transition in diet leads to exponential growth in juveniles and is essential for individuals to reach maturity. Because smaller individuals experience higher mortality and growth is stunted on an algal diet, the ontogenetic shift to corallivory enhances individual fitness and replenishment success. Our findings suggest that the availability of coral prey facilitates early ontogenetic diet shifts and may be fundamental in initiating population irruptions.

scholarly journals Long-term study shows that increasing body size in response to warmer summers is associated with a higher mortality risk in a long-lived bat species

2021 ◽  
Vol 288 (1952) ◽  
pp. 20210508
Author(s):  
Carolin Mundinger ◽  
Alexander Scheuerlein ◽  
Gerald Kerth
Keyword(s):  
Global Warming ◽  
Body Size ◽  
Mortality Risk ◽  
Time Window ◽  
Population Growth Rates ◽  
Individual Fitness ◽  
Long Term Study ◽  
Body Sizes ◽  
Myotis Bechsteinii ◽  
June July

Change in body size is one of the universal responses to global warming, with most species becoming smaller. While small size in most species corresponds to low individual fitness, small species typically show high population growth rates in cross-species comparisons. It is unclear, therefore, how climate-induced changes in body size ultimately affect population persistence. Unravelling the relationship between body size, ambient temperature and individual survival is especially important for the conservation of endangered long-lived mammals such as bats. Using an individual-based 24-year dataset from four free-ranging Bechstein's bat colonies ( Myotis bechsteinii ), we show for the first time a link between warmer summer temperatures, larger body sizes and increased mortality risk. Our data reveal a crucial time window in June–July, when juveniles grow to larger body sizes in warmer conditions. Body size is also affected by colony size, with larger colonies raising larger offspring. At the same time, larger bats have higher mortality risks throughout their lives. Our results highlight the importance of understanding the link between warmer weather and body size as a fitness-relevant trait for predicting species-specific extinction risks as consequences of global warming.

Prey tell: what quillback rockfish early life history traits reveal about their survival in encounters with juvenile coho salmon

2020 ◽  
Vol 650 ◽  
pp. 7-18 ◽  
Author(s):  
HW Fennie ◽  
S Sponaugle ◽  
EA Daly ◽  
RD Brodeur
Keyword(s):  
Life History ◽  
Early Life ◽  
Life History Traits ◽  
Direct Evidence ◽  
Coho Salmon ◽  
Larval Fish ◽  
Early Life History ◽  
In The Wild ◽  
Otolith Microstructure Analysis ◽  
Pelagic Juvenile

Predation is a major source of mortality in the early life stages of fishes and a driving force in shaping fish populations. Theoretical, modeling, and laboratory studies have generated hypotheses that larval fish size, age, growth rate, and development rate affect their susceptibility to predation. Empirical data on predator selection in the wild are challenging to obtain, and most selective mortality studies must repeatedly sample populations of survivors to indirectly examine survivorship. While valuable on a population scale, these approaches can obscure selection by particular predators. In May 2018, along the coast of Washington, USA, we simultaneously collected juvenile quillback rockfish Sebastes maliger from both the environment and the stomachs of juvenile coho salmon Oncorhynchus kisutch. We used otolith microstructure analysis to examine whether juvenile coho salmon were age-, size-, and/or growth-selective predators of juvenile quillback rockfish. Our results indicate that juvenile rockfish consumed by salmon were significantly smaller, slower growing at capture, and younger than surviving (unconsumed) juvenile rockfish, providing direct evidence that juvenile coho salmon are selective predators on juvenile quillback rockfish. These differences in early life history traits between consumed and surviving rockfish are related to timing of parturition and the environmental conditions larval rockfish experienced, suggesting that maternal effects may substantially influence survival at this stage. Our results demonstrate that variability in timing of parturition and sea surface temperature leads to tradeoffs in early life history traits between growth in the larval stage and survival when encountering predators in the pelagic juvenile stage.

scholarly journals A Farewell to the Encephalization Quotient: A New Brain Size Measure for Comparative Primate Cognition

2021 ◽  
pp. 1-12
Author(s):  
Carel P. van Schaik ◽  
Zegni Triki ◽  
Redouan Bshary ◽  
Sandra A. Heldstab
Keyword(s):  
Body Size ◽  
Cognitive Abilities ◽  
Brain Size ◽  
Estimation Error ◽  
Primate Species ◽  
Mammal Species ◽  
Mean Values ◽  
Encephalization Quotient ◽  
Body Sizes ◽  
Size Measure

Both absolute and relative brain sizes vary greatly among and within the major vertebrate lineages. Scientists have long debated how larger brains in primates and hominins translate into greater cognitive performance, and in particular how to control for the relationship between the noncognitive functions of the brain and body size. One solution to this problem is to establish the slope of cognitive equivalence, i.e., the line connecting organisms with an identical bauplan but different body sizes. The original approach to estimate this slope through intraspecific regressions was abandoned after it became clear that it generated slopes that were too low by an unknown margin due to estimation error. Here, we revisit this method. We control for the error problem by focusing on highly dimorphic primate species with large sample sizes and fitting a line through the mean values for adult females and males. We obtain the best estimate for the slope of circa 0.27, a value much lower than those constructed using all mammal species and close to the value expected based on the genetic correlation between brain size and body size. We also find that the estimate of cognitive brain size based on cognitive equivalence fits empirical cognitive studies better than the encephalization quotient, which should therefore be avoided in future studies on primates and presumably mammals and birds in general. The use of residuals from the line of cognitive equivalence may change conclusions concerning the cognitive abilities of extant and extinct primate species, including hominins.

scholarly journals Regional variation in otolith geochemistry of juvenile Atlantic cod (Gadus morhua) in coastal Newfoundland

2016 ◽  
Vol 73 (10) ◽  
pp. 1507-1519 ◽  
Author(s):  
Ryan R.E. Stanley ◽  
Claudio DiBacco ◽  
Simon R. Thorrold ◽  
Paul V.R. Snelgrove ◽  
Corey J. Morris ◽  
...  
Keyword(s):  
Gadus Morhua ◽  
Environmental Variability ◽  
Atlantic Cod ◽  
Environmental Influence ◽  
Spatial Scales ◽  
Early Life History ◽  
Otolith Chemistry ◽  
Geographic Patterns ◽  
Assignment Success ◽  
Scale Classification

We examined spatial variation in otolith geochemistry as a natural tag in juvenile Atlantic cod (Gadus morhua) to resolve geographic patterns during early life history. Individuals from 54 inshore sites spanned five embayments in eastern Newfoundland. Otolith composition differed at all spatial scales and related inversely to spatial scale. Classification analysis revealed increasing discrimination at coarser spatial scales: site (26%–58%), bay (49%), and coast (76%). Assignment success declined by ∼10% per added site with increasing sampling sites per bay, demonstrating fine-scale (<100 km) variation. When we partitioned environmental variability from observed otolith chemistry using predictive models, assignment success improved by 56%, 14%, and 5% for site, bay, and coast, respectively. Our results demonstrate environmental influence on spatial structure of otolith chemistry and illustrate the importance of resolving baseline variability in otolith chemistry when conducting assignment tests. Collectively, our results describe the potential utility of juvenile otolith composition in evaluating contributions of subpopulations to the Northwest Atlantic cod stock and highlight important limitations imposed by environmental variation at scales less than 100 km.

scholarly journals Density and body size of the larval stages of the invasive golden mussel (Limnoperna fortunei) in two neotropical rivers

2012 ◽  
Vol 23 (3) ◽  
pp. 282-292 ◽  
Author(s):  
Vivianne Eilers ◽  
Márcia Divina de Oliveira ◽  
Kennedy Francis Roche
Keyword(s):  
Body Size ◽  
Larval Stage ◽  
Larval Density ◽  
Limnoperna Fortunei ◽  
Larval Size ◽  
Larval Stages ◽  
Positive Effects ◽  
Paraguay River ◽  
Body Sizes ◽  
Golden Mussel

AIM: The present study involved an analysis of the monthly variations in the population densities and body sizes of the different stages of planktonic larvae of the invasive golden mussel (Limnoperna fortunei), in the rivers Paraguay and Miranda; METHODS: The study was carried out between February 2004 and January 2005. Monthly collection of the plankton samples was accompanied by physical, chemical and biological analyses of the water; RESULTS: The Miranda River presented higher values of calcium, pH, alkalinity, conductivity and total phosphorous. Larval density varied from 0-24 individuals.L-1 in the Paraguay River, with a peak in March of 2004, while in the Miranda River, densities varied between 0-9 individuals.L-1 with a peak in February of 2004. No larvae were encountered during the coldest months, May and June. No significant correlations were found between environmental variables and larval density in either river. Only the valved larval stages were recorded. The "D" and veliger forms were most abundant; umbonate larvae were rare in the Miranda River samples. Mean body sizes of "D", veliger and umbonate larval stages were, respectively, 111, 135 and 152 µm, in the Paraguay River, and 112, 134 and 154 µm in the Miranda River. Principal Components Analysis indicated positive relationships between "D" larval stage size and the ratio between inorganic and organic suspended solids, while negative relationships were found between larval size and calcium and chlorophyll-<img border=0 width=7 height=8 src="/img/revistas/alb/2012nahead/ALB_AOP_230307car01.jpg">; CONCLUSIONS: The larvae were recorded in the plankton during most of the year, with the exception of the two colder months. Neither densities nor larval stage body sizes were significantly different between the two rivers. Possible positive effects of food and calcium concentrations on body size were not recorded. This species may be adapted to grow in environments with elevated sediment concentrations.

scholarly journals Body Size Preferences and Food Choice Among Normal and Overweight Mothers and Children in Malawi (P10-070-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Valerie Flax ◽  
Chrissie Thakwalakwa ◽  
Lindsay Jaacks ◽  
John Phuka
Keyword(s):  
Body Size ◽  
Food Choice ◽  
Weight Status ◽  
Food Choices ◽  
Normal Weight ◽  
Sub Saharan Africa ◽  
Overweight Child ◽  
Mothers And Children ◽  
Body Sizes ◽  
Healthy Body

Abstract Objectives Overweight in mothers and children in sub-Saharan Africa is rapidly increasing and may be related to body size preferences. The objective of this study was to measure mothers’ preferences for their own and their child's body size and how they relate to food choices. Methods We enrolled 271 mothers and their children (6–59 months) in Lilongwe and Kasungu Districts. Based on standard body-mass index and weight-for-height z-score cutoffs, 78 mothers (29%) were normal weight and 193 (71%) were overweight; 120 children (44%) were normal weight and 151 (56%) were overweight. Interviewers used a set of 7 adult female and 7 child body silhouette drawings and a semi-structured question guide to measure mothers’ perceptions of their own and their child's preferred and healthy body sizes and how their preferences affected food choices. We performed chi-squared tests comparing body size perceptions and grouped open-ended responses by weight status. Results Mothers’ selection of silhouettes that represented their body size preferences (67% normal weight, 68% overweight preferred overweight) and perceptions of a healthy body size (96% normal weight, 94% overweight selected overweight as healthy) did not differ by their weight status. A higher percentage of mothers of overweight than normal weight children preferred overweight child body sizes (70% vs. 48%, P = 0.003). Mothers’ perceptions of a healthy child body size (89% normal weight, 94% overweight selected overweight as healthy) did not differ by the child's weight status. To attain a larger body size, mothers said they could eat or feed the child larger quantities or more frequently and increase consumption of fatty/oily foods and drinks (such as sodas, sweetened yoghurt, and milk), but many cannot afford to do this. Conclusions Malawian mothers had strong preferences for overweight body sizes for themselves and mixed preferences for their children. Their desired strategies for increasing weight indicate that body size preferences may drive food choice but could be limited by cost. Funding Sources Drivers of Food Choice (DFC) Competitive Grants Program, funded by the UK Government's Department for International Development and the Bill & Melinda Gates Foundation, and managed by the University of South Carolina, Arnold School of Public Health.

Serum Levels of Melatonin in Cancer Patients and their Relation to Body Sizes

1988 ◽  
Vol 3 (3) ◽  
pp. 193-196 ◽  
Author(s):  
S. Barni ◽  
P. Lissoni ◽  
S. Crispino ◽  
F. Rovelli ◽  
G. Esposti ◽  
...  
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Cancer Patients ◽  
Serum Levels ◽  
Blood Levels ◽  
Melatonin Secretion ◽  
Normal Range ◽  
Blood Concentrations ◽  
Patients With Cancer ◽  
Body Sizes

Melatonin secretion is often enhanced in patients with cancer. In the light of a reported correlation between melatonin levels and body size, we investigated blood levels of this pineal hormone in a group of 72 patients affected by cancer, 30 of whom had body weight within the normal range, 30 were obese and the last 12 cases had body weight below the normal range, in order to establish whether in fact melatonin blood concentrations were related to body size. Melatonin levels were high in 19/72 patients (26%). The mean levels of the pineal hormone were similar in patients with normal, low and high body weight. Finally, there was no significant correlation between melatonin values and body weight, height or surface. Melatonin secretion thus does not appear to be influenced by body size in cancer patients.

Sign in / Sign up

Export Citation Format

Share Document