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.

scholarly journals Effects of early life stage exposure of largemouth bass to atrazine or a model estrogen (17α-ethinylestradiol)

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9614
Author(s):  
Jessica K. Leet ◽  
Catherine A. Richter ◽  
Robert S. Cornman ◽  
Jason P. Berninger ◽  
Ramji K. Bhandari ◽  
...  
Keyword(s):  
Gene Expression ◽  
Early Development ◽  
Largemouth Bass ◽  
Early Life ◽  
Micropterus Salmoides ◽  
Life Stage ◽  
Early Life Stage ◽  
Smallmouth Bass ◽  
Gonad Tissue ◽  
And Function

Endocrine disrupting contaminants are of continuing concern for potentially contributing to reproductive dysfunction in largemouth and smallmouth bass in the Chesapeake Bay watershed (CBW) and elsewhere. Exposures to atrazine (ATR) have been hypothesized to have estrogenic effects on vertebrate endocrine systems. The incidence of intersex in male smallmouth bass from some regions of CBW has been correlated with ATR concentrations in water. Fish early life stages may be particularly vulnerable to ATR exposure in agricultural areas, as a spring influx of pesticides coincides with spawning and early development. Our objectives were to investigate the effects of early life stage exposure to ATR or the model estrogen 17α-ethinylestradiol (EE2) on sexual differentiation and gene expression in gonad tissue. We exposed newly hatched largemouth bass (LMB, Micropterus salmoides) from 7 to 80 days post-spawn to nominal concentrations of 1, 10, or 100 µg ATR/L or 1 or 10 ng EE2/L and monitored histological development and transcriptomic changes in gonad tissue. We observed a nearly 100% female sex ratio in LMB exposed to EE2 at 10 ng/L, presumably due to sex reversal of males. Many gonad genes were differentially expressed between sexes. Multidimensional scaling revealed clustering by gene expression of the 1 ng EE2/L and 100 µg ATR/L-treated male fish. Some pathways responsive to EE2 exposure were not sex-specific. We observed differential expression in male gonad in LMB exposed to EE2 at 1 ng/L of several genes involved in reproductive development and function, including star, cyp11a2, ddx4 (previously vasa), wnt5b, cyp1a and samhd1. Expression of star, cyp11a2 and cyp1a in males was also responsive to ATR exposure. Overall, our results confirm that early development is a sensitive window for estrogenic endocrine disruption in LMB and are consistent with the hypothesis that ATR exposure induces some estrogenic responses in the developing gonad. However, ATR-specific and EE2-specific responses were also observed.

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 ◽  
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 Negative Effects of Diurnal Changes in Acidification and Hypoxia on Early-Life Stage Estuarine Fishes

Diversity ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 25 ◽  
Author(s):  
Brooke K. Morrell ◽  
Christopher J. Gobler
Keyword(s):  
Early Life ◽  
Fish Larvae ◽  
Life Stage ◽  
Early Life Stage ◽  
Low Ph ◽  
Sensitivity Threshold ◽  
Diurnal Changes ◽  
Menidia Menidia ◽  
Negative Effects ◽  
Low Do

Estuaries serve as important nursery habitats for various species of early-life stage fish, but can experience cooccurring acidification and hypoxia that can vary diurnally in intensity. This study examines the effects of acidification (pH 7.2–7.4) and hypoxia (dissolved oxygen (DO) ~ 2–4 mg L−1) as individual and combined stressors on four fitness metrics for three species of forage fish endemic to the U.S. East Coast: Menidia menidia, Menidia beryllina, and Cyprinodon variegatus. Additionally, the impacts of various durations of exposure to these two stressors was also assessed to explore the sensitivity threshold for larval fishes under environmentally-representative conditions. C. variegatus was resistant to chronic low pH, while M. menidia and M. beryllina experienced significantly reduced survival and hatch time, respectively. Exposure to hypoxia resulted in reduced hatch success of both Menidia species, as well as diminished survival of M. beryllina larvae. Diurnal exposure to low pH and low DO for 4 or 8 h did not alter survival of M. beryllina, although 8 or 12 h of daily exposure through the 10 days posthatch significantly depressed larval size. In contrast, M. menidia experienced significant declines in survival for all intervals of diel cycling hypoxia and acidification (4–12 h). Exposure to 12-h diurnal hypoxia generally elicited negative effects equal to, or of greater severity, than chronic exposure to low DO at the same levels despite significantly higher mean DO exposure concentrations. This evidences a substantial biological cost to adapting to changing DO levels, and implicates diurnal cycling of DO as a significant threat to fish larvae in estuaries. Larval responses to hypoxia, and to a lesser extent acidification, in this study on both continuous and diurnal timescales indicate that estuarine conditions throughout the spawning and postspawn periods could adversely affect stocks of these fish, with diverse implications for the remainder of the food web.

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.

Toxicity of ammonia to early life stages of the smallmouth bass at four pH values

1985 ◽  
Vol 4 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Steven Broderius ◽  
Robert Drummond ◽  
James Fiandt ◽  
Christine Russom
Keyword(s):  
Early Life ◽  
Smallmouth Bass ◽  
Life Stages ◽  
Early Life Stages ◽  
Ph Values
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