Growth Rate and Survival in Pure Population Matings and Crosses of the Oyster Crassostrea virginica

1983 ◽  
Vol 40 (7) ◽  
pp. 948-954 ◽  
Author(s):  
Andre L. Mallet ◽  
L. E. Haley
Keyword(s):  
Shell Length ◽  
Phenotypic Variability ◽  
Natural Populations ◽  
Genetic Enhancement ◽  
Natural Environments ◽  
Growth And Survival ◽  
Phenotypic Differences ◽  
Genetic Groups ◽  
Commercially Important ◽  
Growth Characters

Phenotypic differences were observed among pure population matings and crosses grown in two natural environments for the following characters: larval shell length, juvenile and adult shell length, weight, and survival at different times. For growth characters, the phenotypic variability between locations was greater than the variability among genetic groups within locations; however, the magnitude of the differences depended on the locality. The crosses exhibited higher survival than pure population matings, and locality had no effect on survival. In growth and survival, some crosses deviated positively from the mean of the parental populations. This may be a manifestation of heterosis. The genetic enhancement of commercially important characters in shellfish will eventually require the formation of a closed breeding unit with a broad genetic base for domestication and selection. It is recommended that an evaluation of natural populations as outlined in this study is a necessary prerequisite to achieve this objective.

scholarly journals THE IMPACT OF MISTRANSLATION ON PHENOTYPIC VARIABILITY AND FITNESS

2020 ◽  
Author(s):  
Laasya Samhita ◽  
Parth K Raval ◽  
Godwin Stephenson ◽  
Shashi Thutupalli ◽  
Deepa Agashe
Keyword(s):  
Phenotypic Variation ◽  
Growth Parameters ◽  
Single Cells ◽  
Phenotypic Variability ◽  
Natural Populations ◽  
Population Level ◽  
Level Variation ◽  
Growth And Survival ◽  
Translation Errors ◽  
The Impact

ABSTRACTPhenotypic variation is widespread in natural populations, and can significantly alter their ecology and evolution. Phenotypic variation often reflects underlying genetic variation, but also manifests via non-heritable mechanisms. For instance, translation errors result in about 10% of cellular proteins carrying altered sequences. Thus, proteome diversification arising from translation errors can potentially generate phenotypic variability, in turn increasing variability in the fate of cells or of populations. However, this link remains unverified. We manipulated mistranslation levels in Escherichia coli, and measured phenotypic variability between single cells (individual level variation), as well as replicate populations (population level variation). Monitoring growth and survival, we find that mistranslation indeed increases variation across E. coli cells, but does not consistently increase variability in growth parameters across replicate populations. Interestingly, although any deviation from the wild type (WT) level of mistranslation reduces fitness in an optimal environment, the increased variation is associated with a survival benefit under stress. Hence, we suggest that mistranslation-induced phenotypic variation can impact growth and survival and has the potential to alter evolutionary trajectories.

scholarly journals Natural variation in social conditions affects male mate choosiness in the amphipod Gammarus roeselii

2021 ◽  
Author(s):  
Konrad Lipkowski ◽  
Sophie Steigerwald ◽  
Lisa M Schulte ◽  
Carolin Sommer-Trembo ◽  
Jonas Jourdan
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Natural Variation ◽  
Natural Populations ◽  
Social Background ◽  
Social Conditions ◽  
Background Information ◽  
Male Mating ◽  
Natural Environments ◽  
Male Mate

Abstract The extent of male mate choosiness is driven by a trade-off between various environmental factors associated with the costs of mate acquisition, quality assessment and opportunity costs. Our knowledge about natural variation in male mate choosiness across different populations of the same species, however, remains limited. In this study, we compared male mate choosiness across 10 natural populations of the freshwater amphipod Gammarus roeselii (Gervais 1835), a species with overall high male mating investments, and evaluated the relative influence of population density and sex ratio (both affecting mate availability) on male mate choosiness. We investigated amplexus establishment after separating mating pairs and presenting focal males with a novel, size-matched female from the same population. Our analysis revealed considerable effects of sex ratio and (to a lesser extent) population density on time until amplexus establishment (choosiness). Male amphipods are able to perceive variable social conditions (e.g., sex ratio) and modify their mating strategy accordingly: We found choosiness to be reduced in increasingly male-biased populations, whereas selectivity increases when sex ratio becomes female biased. With this, our study expands our limited knowledge on natural variations in male mate choosiness and illustrates the importance of sex ratio (i.e., level of competition) for male mating decisions in natural environments. Accounting for variation in sex ratios, therefore, allows envisioning a distinctive variation of choosiness in natural populations and highlights the importance of considering social background information in future behavioral studies.

Tales of lizard tails: effects of tail autotomy on subsequent survival and growth of free-ranging hatchling Uta stansburiana

1997 ◽  
Vol 75 (4) ◽  
pp. 542-548 ◽  
Author(s):  
P. H. Niewiarowski ◽  
J. D. Congdon ◽  
A. E. Dunham ◽  
L. J. Vitt ◽  
D. W. Tinkle
Keyword(s):  
Natural Populations ◽  
Reproductive Investment ◽  
Experimental Manipulation ◽  
Costs And Benefits ◽  
Growth And Survival ◽  
Large Sample ◽  
Uta Stansburiana ◽  
Tail Autotomy ◽  
Trade Offs ◽  
Free Ranging

Potential costs and benefits of tail autotomy in lizards have been inferred almost exclusively from experimental study in semi-natural enclosures and from indirect comparative evidence from natural populations. We present complementary evidence of the costs of tail autotomy to the lizard Uta stansburiana from detailed demographic study of a natural population. On initial capture, we broke the tails of a large sample of free-ranging hatchlings (560) and left the tails of another large sample (455) intact, and then followed subsequent hatchling growth and survival over a 3-year period. Surprisingly, in 1 out of the 3 years of study, survival of female hatchlings with broken tails exceeded that of female hatchlings with intact tails. Furthermore, no effects of tail loss on survivorship were detected for male hatchlings. However, in 2 years when recaptures were very frequent (1961, 1962), growth rates of hatchlings with broken tails were significantly slower than those of their counterparts with intact tails. We discuss our results in the broader context of estimating the relative costs and benefits of tail autotomy in natural populations, and suggest that long-term demographic studies will provide the best opportunity to assess realized fitness costs and benefits with minimum bias. We also describe how experimentally induced tail autotomy can be used as a technique to complement experimental manipulation of reproductive investment in the study of life-history trade-offs.

Morphologic variations of periwinkle and profiles of periwinkle marketers and harvesters in two states in the Niger delta area of Nigeria

2015 ◽  
Vol 11 (2) ◽  
pp. 140-147
Author(s):  
M Okpeku ◽  
MB Nodu ◽  
A Essien ◽  
CT Fekorigha
Keyword(s):  
Shell Length ◽  
Niger Delta ◽  
Age Groups ◽  
Work Force ◽  
Omega 3 ◽  
Intertidal Zones ◽  
Phenotypic Differences ◽  
Aged People ◽  
Market Women ◽  
Rivers State

Periwinkles are invertebrates rich in protein and omega-3 fatty acids. These make them relished delicacies. Three hundred and fifteen (315) individual periwinkles were hand-picked from mangrove swamp river banks and intertidal zones of Twon-Brass in Bayelsa State and Abonnema town of Rivers State. Shell length and the weight of both the meat and shell were taken with Veneer caliper and a sensitive electronic scale balance respectively. Information on the economics of production was gathered from market women and harvesters through the use of structured questionnaires. The present study indentified possible phenotypic differences among periwinkle harvested in Bayelsa and Rivers States base on shell length and meat weight differences. Periwinkle harvested in Rivers is bigger and heavier than those harvested in Bayelsa State. Prediction of meat and total weight of from shell length was done using regression analysis. The study also identified the involvement of the different age groups that form the work-force in the States; showing that there are more young adults and teenagers in the business of harvesting and sales than aged people. There are more men involved in the business than women. There is a decline in size, quantity and availability of periwinkle presently than in the past, a factor that could be attributed to over-harvesting.Key Words: Bayelsa, Morphology, Niger Delta, Periwinkle, Rivers.

scholarly journals Effects of low-pH stress on shell traits of the dove snail, <i>Anachis misera</i>, inhabiting shallow-vent environments off Kueishan Islet, Taiwan

2015 ◽  
Vol 12 (9) ◽  
pp. 2631-2639 ◽  
Author(s):  
Y. J. Chen ◽  
J. Y. Wu ◽  
C. T. A. Chen ◽  
L. L. Liu
Keyword(s):  
Shell Length ◽  
Shell Thickness ◽  
Expression Profiles ◽  
Shell Shape ◽  
Natural Environments ◽  
Additional Information ◽  
Shell Width ◽  
T1 And T2 ◽  
Body Whorl ◽  
Protein Expression Profiles

Abstract. The effects of naturally acidified seawater on shell traits were quantified through the comparison of dove snails (Family: Columbellidae) Anachis misera from vent environments with Euplica sp. from non-vent sites in northeastern Taiwan. Samples of A. misera were collected around a shallow vent (24.8341° N, 121.96191° E), which included the east, south, southwest, and northwest sites. An absence of Anachis snails was found in the most acidic north site (pH 7.19–7.25). Based on the similarities of protein expression profiles, the Anachis snails were classified into two groups, i.e., V-South (pH 7.78–7.82) and V-Rest (pH 7.31–7.83). Comparing their shell traits to the non-vent Euplica sp. from Da-xi (DX) and Geng-fang (GF) (pH 8.1–8.2), a difference in shell shape (shell width : shell length) was found, with the populations having more globular shells than the non-vent ones. The means of shell width were significantly different among sites (p < 0.01), with a descending order of GF > DX > V-South and V-Rest. The relationships of shell length to total weight were curvilinear for both Anachis and Euplica snails. The logarithmically transformed slopes differed significantly among sites, and the mean body weight of the GF population was greater than that of the others (p < 0.01). Positive correlations between shell length and shell thickness of body whorl (T1) and penultimate whorl (T2) were only observed in non-vent GF and DX populations. Anachis snails from vent sites were thinner in T1 and T2 compared to the Euplica snails from non-vent sites (p < 0.05). Within each vent group, shell thickness between T1 and T2 was insignificantly different. Between vent groups, T1 and T2 from V-Rest showed a decrease of 10.6 and 10.2%, respectively, compared to V-South ones. The decrease of T1 and T2 between vent Anachis snails and non-vent Euplica snails was as great as 55.6 and 29.0%, respectively. This was the first study to compare snail's morphological traits under varying shallow-vent stresses with populations previously classified by biochemical responses. Overall, the shallow-vent-based findings provide additional information from subtropics on the effects of acidified seawater on gastropod snails in natural environments.

scholarly journals Pampean lizard assemblage from subtropical Brazil: a temporal analysis

2011 ◽  
Vol 83 (4) ◽  
pp. 1345-1358 ◽  
Author(s):  
Gisele R. Winck ◽  
Tiago G. Dos Santos ◽  
Sonia Z. Cechin
Keyword(s):  
Environmental Changes ◽  
Seasonal Pattern ◽  
Natural Populations ◽  
Temporal Analysis ◽  
Natural Environments ◽  
Human Occupation ◽  
Environmental Disturbances ◽  
Pampa Biome ◽  
History Of ◽  
Recruitment Period

The increasing human occupation of natural environments is one of the greatest threats to biodiversity. To mitigate the negative anthropogenic effects, it is necessary to understand the characteristics of natural populations and the natural history of species. A study was conducted with an assemblage of lizards from a disturbed area of the Pampa biome, from February 2001 to January 2004. The assemblage showed a unimodal seasonal pattern, with the recruitment period occurring during the warmer months. The captures were seasonal for two of the three monitored years, and concentrated within warmer months. The minimum temperature explained the number of catches for the assemblage as a whole. However, when the species were analyzed individually, the temperature only explained the seasonal occurrence of Teius oculatus. The abundance of species was significantly different in the third year of study for Cercosaura schreibersii and Ophiodes striatus. This latter species was no longer registered in the study area from May 2003 until the end of the study. Therefore, O. striatus may be more sensitive to environmental changes, considering the events of change in vegetation during the study. With frequent and increasing environmental disturbances, it is necessary to take conservation measures and encourage the increase of knowledge on Pampean lizards.

scholarly journals Genome-wide shifts in climate-related variation underpin responses to selective breeding in a widespread conifer

2021 ◽  
Vol 118 (10) ◽  
pp. e2016900118
Author(s):  
Ian R. MacLachlan ◽  
Tegan K. McDonald ◽  
Brandon M. Lind ◽  
Loren H. Rieseberg ◽  
Sam Yeaman ◽  
...  
Keyword(s):  
Gene Flow ◽  
Selective Breeding ◽  
Natural Populations ◽  
Cold Injury ◽  
Nucleotide Polymorphisms ◽  
Phenotypic Differences ◽  
Climatic Regions ◽  
Breeding Populations ◽  
Trade Offs ◽  
Growth Initiation

Locally adapted temperate tree populations exhibit genetic trade-offs among climate-related traits that can be exacerbated by selective breeding and are challenging to manage under climate change. To inform climatically adaptive forest management, we investigated the genetic architecture and impacts of selective breeding on four climate-related traits in 105 natural and 20 selectively bred lodgepole pine populations from western Canada. Growth, cold injury, growth initiation, and growth cessation phenotypes were tested for associations with 18,600 single-nucleotide polymorphisms (SNPs) in natural populations to identify “positive effect alleles” (PEAs). The effects of artificial selection for faster growth on the frequency of PEAs associated with each trait were quantified in breeding populations from different climates. Substantial shifts in PEA proportions and frequencies were observed across many loci after two generations of selective breeding for height, and responses of phenology-associated PEAs differed strongly among climatic regions. Extensive genetic overlap was evident among traits. Alleles most strongly associated with greater height were often associated with greater cold injury and delayed phenology, although it is unclear whether potential trade-offs arose directly from pleiotropy or indirectly via genetic linkage. Modest variation in multilocus PEA frequencies among populations was associated with large phenotypic differences and strong climatic gradients, providing support for assisted gene flow polices. Relationships among genotypes, phenotypes, and climate in natural populations were maintained or strengthened by selective breeding. However, future adaptive phenotypes and assisted gene flow may be compromised if selective breeding further increases the PEA frequencies of SNPs involved in adaptive trade-offs among climate-related traits.

scholarly journals Survival, growth, and morphology of blue king crabs: effect of ocean acidification decreases with exposure time

2016 ◽  
Vol 74 (4) ◽  
pp. 1033-1041 ◽  
Author(s):  
William Christopher Long ◽  
Scott B. Van Sant ◽  
Katherine M. Swiney ◽  
Robert J. Foy
Keyword(s):  
Mortality Rate ◽  
Ocean Acidification ◽  
Morphological Changes ◽  
Phenotypic Variability ◽  
Minor Effect ◽  
King Crab ◽  
Growth And Survival ◽  
Blue King Crab ◽  
Paralithodes Platypus ◽  
A Minor

Ocean acidification is an altering marine carbonate chemistry resulting in potential effects to marine life. In this study, we determine the effects of decreased pH on the morphology, growth, and survival of juvenile blue king crab, Paralithodes platypus. Crabs were reared at three pH levels: ambient (control, pH ∼8.1), pH 7.8, and pH 7.5, for 1 year and monitored for morphological changes, survival, and growth. Exposure to seawater at pH 7.8 had no effect on morphology or mortality and had only a minor effect on growth compared with the ambient treatment. However, exposure to seawater at pH 7.5 substantially increased mortality and decreased growth compared with the ambient treatment. The best fit model of mortality rate at pH 7.5 showed an initially high mortality rate, which dropped to become comparable to the mortality rate in the other treatments. This suggests phenotypic variability or plasticity in juveniles and may indicate acclimation by blue king crab to ocean acidification. As such, blue king crab may have scope for evolutionary adaptation in response to gradually changing pH levels. However, effects on other life-history stages, sub-lethal effects, carryover or transgenerational effects, and interactions with other stressors, such as increased temperature, still need to be investigated.

scholarly journals Biogeography of the Purple Nonsulfur Bacterium Rhodopseudomonas palustris

2003 ◽  
Vol 69 (9) ◽  
pp. 5186-5191 ◽  
Author(s):  
Yasuhiro Oda ◽  
Bastiaan Star ◽  
Louis A. Huisman ◽  
Jan C. Gottschal ◽  
Larry J. Forney
Keyword(s):  
Rhodopseudomonas Palustris ◽  
Natural Populations ◽  
Rrna Gene ◽  
Similarity Coefficients ◽  
Phenotypic Differences ◽  
Purple Nonsulfur Bacterium ◽  
Sampling Locations ◽  
Genomic Fingerprint ◽  
Source Use ◽  
Kinetics Of

ABSTRACT The biogeography of the purple nonsulfur bacterium Rhodopseudomonas palustris on a local scale was investigated. Thirty clones of phototrophic bacteria were isolated from each of five unevenly spaced sampling locations in freshwater marsh sediments along a linear 10-m transect, and a total of 150 clones were characterized by BOX-PCR genomic DNA fingerprinting. Cluster analysis of 150 genomic fingerprints yielded 26 distinct genotypes, and 106 clones constituted four major genotypes that were repeatedly isolated. Representatives of these four major genotypes were tentatively identified as R. palustris based on phylogentic analyses of 16S rRNA gene sequences. The differences in the genomic fingerprint patterns among the four major genotypes were accompanied by differences in phenotypic characteristics. These phenotypic differences included differences in the kinetics of carbon source use, suggesting that there may be functional differences with possible ecological significance among these clonal linages. Morisita-Horn similarity coefficients (C MH), which were used to compare the numbers of common genotypes found at pairs of sampling locations, showed that there was substantial similarity between locations that were 1 cm apart (C MH, ≥0.95) but there was almost no similarity between locations that were ≥9 m apart (C MH, ≤0.25). These calculations showed there was a gradual decrease in similarity among the five locations as a function of distance and that clones of R. palustris were lognormally distributed along the linear 10-m transect. These data indicate that natural populations of R. palustris are assemblages of genetically distinct ecotypes and that the distribution of each ecotype is patchy.

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