Deriving population scaling rules from individual-level metabolism and life history traits

2021 ◽  
Author(s):  
Rémy Denéchère ◽  
P. Daniël van Denderen ◽  
Ken Haste Andersen
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Individual Level

Impact of density and sex-dependent larval competition on selected life history traits ofDrosophila melanogaster(Diptera: Drosophilidae)

2017 ◽  
Vol 150 (1) ◽  
pp. 87-99
Author(s):  
Sohini Singha Roy ◽  
Gautam Aditya ◽  
Sujay Ghosh
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Larval Density ◽  
Adult Survival ◽  
Larval Rearing ◽  
Individual Level ◽  
Adult Body ◽  
Rearing Density ◽  
Competitive Behaviour ◽  
The Individual

AbstractAn assessment of the effects of competitive behaviour and sex on seven selected life history traits ofDrosophila melanogasterMeigen (Diptera: Drosophilidae) was made under precisely regulated larval density. Contrary to the conditions of crowding, as considered in many previous studies, the low scale of density enabled assessment of the life history traits at the individual level with higher precision and low variations. The 0-day-old first instars were reared with the relative density of 1,2, 3, and 4 individuals with optimal food until the adults emerged. The life history traits like age at pupation, age at eclosion, adult body weight, adult body length, wing length, and adult survival were used as response variables. Both the density and sex of the competitors were considered as predictors of the life history traits and a stronger effect was evident in the female sex than in males, which is statistically significant. Result also revealed the effect of competitive behaviour was more intense in case of same sex competitors than of opposite sex. In all instances, the life history traits exhibited a trend of decreasing function with the increasing larval rearing density, in compliance with the norms of density-dependent effects on development ofDrosophilaFallén and similar insects.

scholarly journals Behaviour and body patterns of Octopus vulgaris facing a baited trap: first-capture assessment

2021 ◽  
Vol 85 (1) ◽  
pp. e003
Author(s):  
Marta Dominguez-Lopez ◽  
Guillermo Follana-Berná ◽  
Pablo Arechavala-Lopez
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Small Scale ◽  
Octopus Vulgaris ◽  
Body Postures ◽  
Individual Level ◽  
Baited Traps ◽  
Population Consequences ◽  
Body Patterns ◽  
First Time

This study highlights for the first time individual differences in ethology and vulnerability of Octopus vulgaris (i.e. body postures, movements and skin displays) facing passive baited traps. Common octopus exposed to a baited trap during three consecutive first-capture tests exhibited diverse behavioural and body pattern sequences resembling when the octopus searches for and hunts its wild prey. Overall, they first visually recognized new objects or potential preys and rapidly moved out of the den, exploring, grabbing and approaching the trap with the arms (chemotactile exploration), and capturing the bait with the arms and feeding on top over long periods inside the trap. Simultaneously, O. vulgaris displayed diverse skin textural and chromatic signs, the regular pattern being the most frequent and long-lasting, followed by broad mottle, passing cloud and dark patterns. All individuals (n=8) caught the bait at least once, although only five octopuses (62.5%) entered the trap in all three tests. In addition, high variability among individuals was observed regarding behaviour and body patterns during the first-capture tests, which might evidence different individual temperaments or life-history traits. Differences in behavioural responses at individual level might have population consequences due to fisheries-induced selection, although there is a high necessity to assess how behavioural traits might play an important role in life-history traits of this species harvested by small-scale trap fisheries.

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.

Life History Traits in a Population of Pelobates syriacus (Boettger, 1889) from Turkey

2020 ◽  
Vol 27 (4) ◽  
pp. 195-200
Author(s):  
Ufuk Bülbül ◽  
Halime Koç ◽  
Yasemin Odabaş ◽  
Ali İhsan Eroğlu ◽  
Muammer Kurnaz ◽  
...  
Keyword(s):  
Life History ◽  
Age Structure ◽  
Life History Traits ◽  
Spadefoot Toad ◽  
Males And Females

Age structure of the eastern spadefoot toad, Pelobates syriacus from the Kızılırmak Delta (Turkey) were assessed using phalangeal skeletochronology. Snout-vent length (SVL) ranged from 42.05 to 86.63 mm in males and 34.03 to 53.27 mm in females. Age of adults ranged from 2 to 8 years in males and 3 to 5 years in females. For both sexes, SVL was significantly correlated with age. Males and females of the toads reached maturity at 2 years of age.

Hormones and Behavior

2019 ◽  
pp. 11-26
Author(s):  
Maren N. Vitousek ◽  
Laura A. Schoenle
Keyword(s):  
Life History ◽  
Life Histories ◽  
Life History Traits ◽  
Developmental Plasticity ◽  
Endocrine System ◽  
Phenotypic Traits ◽  
Social Environments ◽  
Trade Offs ◽  
And Behavior

Hormones mediate the expression of life history traits—phenotypic traits that contribute to lifetime fitness (i.e., reproductive timing, growth rate, number and size of offspring). The endocrine system shapes phenotype by organizing tissues during developmental periods and by activating changes in behavior, physiology, and morphology in response to varying physical and social environments. Because hormones can simultaneously regulate many traits (hormonal pleiotropy), they are important mediators of life history trade-offs among growth, reproduction, and survival. This chapter reviews the role of hormones in shaping life histories with an emphasis on developmental plasticity and reversible flexibility in endocrine and life history traits. It also discusses the advantages of studying hormone–behavior interactions from an evolutionary perspective. Recent research in evolutionary endocrinology has provided insight into the heritability of endocrine traits, how selection on hormone systems may influence the evolution of life histories, and the role of hormonal pleiotropy in driving or constraining evolution.

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