scholarly journals Differences among families in craniofacial shape at early life-stages of Arctic charr (Salvelinus alpinus)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Samantha V. Beck ◽  
Katja Räsänen ◽  
Camille A. Leblanc ◽  
Skúli Skúlason ◽  
Zophonías O. Jónsson ◽  
...  
Keyword(s):  
Early Life ◽  
Egg Size ◽  
Developmental Stages ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Life Stage ◽  
Early Life Stage ◽  
Offspring Size ◽  
Life Stages ◽  
Early Life Stages

Abstract Background Organismal fitness can be determined at early life-stages, but phenotypic variation at early life-stages is rarely considered in studies on evolutionary diversification. The trophic apparatus has been shown to contribute to sympatric resource-mediated divergence in several taxa. However, processes underlying diversification in trophic traits are poorly understood. Using phenotypically variable Icelandic Arctic charr (Salvelinus alpinus), we reared offspring from multiple families under standardized laboratory conditions and tested to what extent family (i.e. direct genetic and maternal effects) contributes to offspring morphology at hatching (H) and first feeding (FF). To understand the underlying mechanisms behind early life-stage variation in morphology, we examined how craniofacial shape varied according to family, offspring size, egg size and candidate gene expression. Results Craniofacial shape (i.e. the Meckel’s cartilage and hyoid arch) was more variable between families than within families both across and within developmental stages. Differences in craniofacial morphology between developmental stages correlated with offspring size, whilst within developmental stages only shape at FF correlated with offspring size, as well as female mean egg size. Larger offspring and offspring from females with larger eggs consistently had a wider hyoid arch and contracted Meckel’s cartilage in comparison to smaller offspring. Conclusions This study provides evidence for family-level variation in early life-stage trophic morphology, indicating the potential for parental effects to facilitate resource polymorphism.

scholarly journals Differences among families in craniofacial shape at early life-stages of Arctic charr (Salvelinus alpinus)

2020 ◽  
Author(s):  
Samantha Victoria Beck ◽  
Katja Räsänen ◽  
Camille A. Leblanc ◽  
Skúli Skúlason ◽  
Zophonías O. Jónsson ◽  
...  
Keyword(s):  
Early Life ◽  
Egg Size ◽  
Developmental Stages ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Life Stage ◽  
Early Life Stage ◽  
Offspring Size ◽  
Life Stages ◽  
Early Life Stages

Abstract Background Organismal fitness can be determined at early life-stages, but phenotypic variation at early life-stages is rarely considered in studies on evolutionary diversification. The trophic apparatus has been shown to contribute to sympatric resource-mediated divergence in several taxa. However, processes underlying diversification in trophic traits are poorly understood. Using phenotypically variable Icelandic Arctic charr (Salvelinus alpinus), we reared offspring from multiple families under standardized laboratory conditions and tested to what extent family (i.e. direct genetic and maternal effects) contributes to offspring morphology at hatching (H) and first feeding (FF). To understand the underlying mechanisms behind early life-stage variation in morphology, we examined how craniofacial shape varied according to family, offspring size, egg size and candidate gene expression. Results Craniofacial shape (i.e. the Meckel’s cartilage and hyoid arch) was more variable between families than within families both across and within developmental stages. Differences in craniofacial morphology between developmental stages correlated with offspring size, whilst within developmental stages only shape at FF correlated with offspring size, as well as female mean egg size. Larger offspring and offspring from females with larger eggs consistently had a wider hyoid arch and contracted Meckel’s cartilage in comparison to smaller offspring.Conclusions This study provides evidence for family-level variation in early life-stage trophic morphology, indicating the potential for parental effects to facilitate resource polymorphism.

scholarly journals Differences among families in craniofacial shape at early life-stages of Arctic charr (Salvelinus alpinus)

2020 ◽  
Author(s):  
Samantha Victoria Beck ◽  
Katja Räsänen ◽  
Camille A. Leblanc ◽  
Skúli Skúlason ◽  
Zophonías O. Jónsson ◽  
...  
Keyword(s):  
Maternal Effects ◽  
Phenotypic Variation ◽  
Early Life ◽  
Egg Size ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Craniofacial Development ◽  
Offspring Size ◽  
Life Stages ◽  
Early Life Stages

Abstract Background Organismal fitness can be determined at early life-stages, but phenotypic variation at these early life-stages has rarely been considered in studies on evolutionary diversification. The trophic apparatus has been shown to contribute to sympatric resource-mediated divergence in several taxa. However, processes underlying this diversification are poorly understood. Using a phenotypically variable morph of Icelandic Arctic charr (Salvelinus alpinus), we reared offspring from multiple families under standardized laboratory conditions and tested to what extent family (i.e. direct genetic and maternal effects) contributes to offspring morphology at hatching (H) and first feeding (FF). To understand the underlying mechanisms behind early life-stage variation in morphology, we examined how craniofacial shape varied according to family, egg size, offspring size and individual candidate genes related to craniofacial development. Finally, we assessed whether craniofacial shape and expression of genes related to craniofacial development covaried. Results We found effects of family for offspring craniofacial shape at both H and FF, whilst relative expression levels of Sgk1 (a gene involved in craniofacial shape divergence) correlated with craniofacial shape at FF. However, there were no evidence to suggest that mean egg size or individual offspring size influenced offspring morphology. Conclusions This study provides evidence for within population family effects for phenotypic variation in trophic morphology, indicating the potential for genetic and/or maternal effects to facilitate resource polymorphism.

Lethality of Low pH and Al to Early Life Stages of Six Fish Species Inhabiting PreCambrian Shield Waters in Ontario

1989 ◽  
Vol 46 (7) ◽  
pp. 1188-1202 ◽  
Author(s):  
K. E. Holtze ◽  
N. J. Hutchinson
Keyword(s):  
Largemouth Bass ◽  
Early Life ◽  
Life Stage ◽  
Early Life Stage ◽  
Low Ph ◽  
Smallmouth Bass ◽  
Life Stages ◽  
White Sucker ◽  
Lake Whitefish ◽  
Early Life Stages

Lethality of low pH and Al to egg and fry stages of common shiner (Notropis cornutus), white sucker (Catostomus commersoni), walleye (Stizostedion vitreum), lake whitefish (Coregonus clupeaformis), smallmouth bass (Micropterus dolomieui), and largemouth bass (M. salmoides) was determined in a series of laboratory tests in soft (Ca = 4.0 mg/L) water. Low pH was lethal to cleavage eggs in the first 4 d of exposure, to eyed eggs in the immediate prehatch period and to fry following their transition to branchial respiration. Early life stage response to Al was determined by their sensitivity to low pH. Al prolonged survival of cleavage eggs at pH = 4.2, was detrimental to eyed eggs and fry at pH 4.4–5.4 and was most lethal within 0.3 pH units of the pH which was lethal in the absence of Al. In situ distribution of four of the six species was adequately explained by lethality of low pH alone to cleavage eggs or fry. Sensitivity to low pH and Al produced estimates of pH > 5.9 (common shiner), pH > 5.4 (lake whitefish, white sucker, walleye), and pH > 5.1 (smallmouth and largemouth bass) for survival of early life stages in acidified waters.

scholarly journals The effect of life stages on needs satisfied by credit used, according to Alderfer’s existence relatedness growth theory

2016 ◽  
Vol 6 (4) ◽  
pp. 324-333
Author(s):  
A. Botha ◽  
J.M.P. Venter
Keyword(s):  
Family Life ◽  
Early Life ◽  
Life Stage ◽  
Early Life Stage ◽  
Growth Theory ◽  
Life Stages ◽  
Early Life Stages ◽  
Product Usage ◽  
The Past ◽  
Educational Programmes

The increase in household debt in South Africa over the past decade illustrates the importance of analysing credit usage. This study investigated the individual’s financial needs satisfied when using credit and the effect of life stage on the needs satisfied. The financial needs satisfied when using credit were analysed according to life stages using Alderfer’s existence relatedness growth (ERG) theory as a framework. The results indicated that credit usage is influenced by an individual’s life stage. This study found that individuals across all life stages mainly use credit to satisfy their existence needs. Although individuals in their single life stages used less credit products than individuals in their family life stages, it was worrisome to ascertain that mature couples had the highest average credit product usage. The findings suggest that individuals fall into the debt trap in their early life stage, resulting in them being unable to save income in the high-income-producing years in order to be able to dissave after retirement. It is suggested that educational programmes targeting the early life stages should be introduced to prevent individuals from becoming overindebted.

Toxicity of TFM (Lampricide) to Six Early Life Stages of Rainbow Trout (Salmo gairdneri)

1973 ◽  
Vol 30 (8) ◽  
pp. 1047-1052 ◽  
Author(s):  
L. E. Olson ◽  
L. L. Marking
Keyword(s):  
Rainbow Trout ◽  
Early Life ◽  
Natural Waters ◽  
Life Stage ◽  
Water Hardness ◽  
Salmo Gairdneri ◽  
Life Stages ◽  
Early Life Stages ◽  
Margin Of Safety ◽  
Coexisting Species

The lampricide TFM (3-trifluoromethyl-4-nitrophenol) was tested against the following life stages of rainbow trout (Salmo gairdneri): green eggs, eyed eggs, sac fry, swim-up fry, fry, and fingerlings in four water hardnesses (12, 44, 170, and 320 mg/liter as CaCO3). The eyed-egg stage was one of the most resistant stages tested, and the sac-fry stage was one of the least resistant. Increased water hardness decreases toxicity to all stages. The LC50’s range from 0.532 mg/liter to 40.0 mg/liter depending upon life stage, water hardness, and duration of exposure. The margin of safety for coexisting species exposed to TFM ranges from 3.2 to 4.1 in natural waters. The margin of safety for early life stages of rainbow trout and larval lamprey under controlled laboratory conditions ranges from 4.2 to 12.2. Therefore, all six early life stages of rainbow trout are safe in minimum lampricidal concentrations of TFM.

scholarly journals Influence of turbulence and in-stream structures on the transport and survival of grass carp eggs and larvae at various developmental stages

2019 ◽  
Vol 82 (1) ◽  
Author(s):  
Andres F. Prada ◽  
Amy E. George ◽  
Benjamin H. Stahlschmidt ◽  
Patrick Ryan Jackson ◽  
Duane C. Chapman ◽  
...  
Keyword(s):  
Grass Carp ◽  
Early Life ◽  
Developmental Stages ◽  
Shear Stresses ◽  
Life Stages ◽  
Early Life Stages ◽  
Field Collection ◽  
Hydrodynamic Experiments ◽  
Active Swimming ◽  
Eggs And Larvae

AbstractUnderstanding the response of grass carp to flow and turbulence regimes during early life stages is fundamental to monitoring and controlling their spread. A comprehensive set of hydrodynamic experiments was conducted with live grass carp eggs and larvae, to better understand their drifting and swimming patterns with 3 different in-stream obstructions: (1) a gravel bump, (2) a single cylinder, and (3) submerged vegetation. The hydrodynamic behavior of eggs and larvae with each obstruction was continuously monitored for about 85 consecutive hours. Transient spatial distributions of the locations of eggs and larvae throughout the water column were generated for each flow scenario. Results show that the active swimming capabilities of larvae allow them to seek areas of low turbulence and low shear stresses, and that eggs are susceptible to damage by high levels of turbulence, which was further corroborated with tests in an oscillating grid-stirred turbulence tank. Our study seeks to better inform field collection of grass carp during early life stages, and to guide the design of alternative approaches to control the dispersal of this invasive species in North America.

Effect of developmental stage and peloton morphology on success in isolation of mycorrhizal fungi in Caladenia formosa (Orchidaceae)

2004 ◽  
Vol 52 (2) ◽  
pp. 231 ◽  
Author(s):  
T. T. Huynh ◽  
A. C. Lawrie ◽  
F. Coates ◽  
C. B. McLean
Keyword(s):  
Mycorrhizal Fungi ◽  
Early Life ◽  
Developmental Stages ◽  
Life Stages ◽  
Early Life Stages ◽  
Terrestrial Orchid ◽  
Leaf Production ◽  
Fruiting Stage ◽  
One Year ◽  
Scanning Electron

Six developmental stages (leafing, budding, flowering, fruiting, senescence and dormancy) were chosen in the threatened terrestrial orchid Caladenia formosa G.W.Carr to optimise isolation of effective fungi. Loose (undigested) pelotons were observed by scanning electron microscopy in the old tuber and collar, suggesting a role in infection of new tissue. In collars collected at early life stages (leafing, budding, flowering), pelotons had loosely coiled hyphae that were uniformly fine (1–2 μm diameter), with or without monilioid cells. In collars collected from older life stages (fruiting, senescence), pelotons had increasing proportions (up to 94%) of clumped fine hyphae. Coarser hyphae (4–6 μm diameter) were also present in the fruiting stage in one year. Only fungi isolated from single pelotons in collars of early life stages (leafing, budding, flowering) had fine hyphae with monilioid cells and induced seed germination (to green leaf production). Sectioned protocorms had pelotons of fine, loosely coiled hyphae with monilioid cells, as in field-collected material from early life stages. This suggests that the most effective fungi for conservation of this orchid are likely to be isolated from pelotons of loose fine hyphae with monilioid cells from leafing to flowering stages.

scholarly journals Cross-Life Stage Effects of Aquatic Larval Density and Terrestrial Moisture on Growth and Corticosterone in the Spotted Salamander

Diversity ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 68 ◽  
Author(s):  
Julie Charbonnier ◽  
Jacquelyn Pearlmutter ◽  
James Vonesh ◽  
Caitlin Gabor ◽  
Zachery Forsburg ◽  
...  
Keyword(s):  
Early Life ◽  
Specific Growth ◽  
Life Stage ◽  
Larval Density ◽  
Life Cycles ◽  
Life Stages ◽  
Early Life Stages ◽  
Release Rates ◽  
Specific Growth Rates ◽  
Corticosterone Release

For organisms with complex life cycles, conditions experienced during early life stages may constrain later growth and survival. Conversely, compensatory mechanisms may attenuate negative effects from early life stages. We used the spotted salamander, Ambystoma maculatum, to test how aquatic larval density and terrestrial moisture influence juvenile growth, food intake, evaporative water loss and water reuptake rates, and corticosterone levels. We conducted an outdoor mesocosm experiment to manipulate larval density and transferred metamorphosed salamanders into low and high terrestrial moisture treatments in laboratory terrariums. After the larval stage, high-density salamanders were significantly smaller and had higher corticosterone release rates than those from low-density treatments. Salamanders in the low terrestrial moisture treatment consumed fewer roaches, had lower mass-specific growth rates, higher water reuptake, and higher corticosterone release rates than salamanders in high terrestrial moisture treatments. Across moisture treatments, smaller salamanders had higher mass-specific growth rates than larger salamanders. Our results suggest that salamanders can partially compensate for competition in the larval aquatic habitat with increased growth as juveniles, but this response is dependent on terrestrial habitat quality. Thus, the persistence of early life stage effects can be an important, yet context-dependent, component of amphibian life cycles.

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