scholarly journals Long-Term Data Reveal the Associations of the Egg Quality With Abiotic Factors and Female Traits in the Baltic Herring Under Variable Environmental Conditions

2021 ◽  
Vol 8 ◽  
Author(s):  
Marjut Rajasilta ◽  
Katja Mäkinen ◽  
Suvi Ruuskanen ◽  
Jari Hänninen ◽  
Päivi Laine

In fish, the lipid resources of the female form a link between the environment and progeny, contributing to the contents of the egg yolk. Variation of the environmental conditions is therefore expected to affect the egg quality via maternal pathways, reflecting the female’s response to the environmental factors before spawning. We investigated the content of lipids and thyroid hormones in the ovary and eggs of the Baltic herring during 1988–2019, when salinity of the Baltic Sea first declined and then stabilized to a lower level, and winters varied between severe and mild. The total lipid resources of spawning females decreased by 40–50% during the study, and the ovarian lipid concentration followed this trend resulting in a decrease of the lipid content of eggs. The concentration of thyroid hormones in the ovary suggested a hormonal response in females to salinity and winter temperature and was observable also in the content of thyroid hormones in the eggs. A change in the egg lipid content took place approximately around 1998 (SE ± 3 years) suggesting that in declining salinity, egg quality was associated with salinity and intrinsic factors in the female, i.e., fecundity and amount of lipids deposited into the ovary. However, during the period of stable salinity, egg quality was mainly limited by the female’s lipid resources. As also the body size of the females decreased over the years, it is suggested that small body size can be a key phenotypic trait to reduce the environmental impact on egg quality in variable environmental conditions.

Author(s):  
Henglong Xu ◽  
Yong Jiang ◽  
Wei Zhang ◽  
Mingzhuang Zhu ◽  
Khaled A. S. Al-Rasheid ◽  
...  

The annual variations in body-size spectra of planktonic ciliate communities and their relationships to environmental conditions were studied based on a 12-month dataset (June 2007 to May 2008) from Jiaozhou Bay on the Yellow Sea coast of northern China. Based on the dataset, the body sizes of the ciliates, expressed as equivalent spherical diameters, included five ranks: S1 (5–35 μm); S2 (35–55 μm); S3 (55–75 μm); S4 (75–100 μm); and S5 (100–350 μm). These body-size ranks showed a clear temporal succession of dominance in the order of S2 (January–April) → S1 (May–July) → S4 (August–September) → S3 (October–December). Multivariate analyses showed that the temporal variations in their body-size patterns were significantly correlated with changes in environmental conditions, especially water temperature, salinity, dissolved oxygen concentration (DO) and nutrients. In terms of abundance, rank S2 was significantly correlated with water temperature, DO and nutrients, whereas ranks S4 and S5 were correlated with the salinity and nutrients respectively (P < 0.05). These results suggest that the body-size patterns of planktonic ciliate communities showed a clear temporal pattern during an annual cycle and significantly associated with environmental conditions in marine ecosystems.


2019 ◽  
Vol 76 (4) ◽  
pp. 576-585 ◽  
Author(s):  
Marjut Rajasilta ◽  
Jari Hänninen ◽  
Lea Laaksonen ◽  
Päivi Laine ◽  
Jukka-Pekka Suomela ◽  
...  

Global climate change can affect the energy content of fish by altering their lipid physiology and consumption. We investigated the effects of different environmental stressors on the lipid content of the Baltic herring (Clupea harengus membras) from spawning ground samples that were collected annually in the northern Baltic Sea. During 1987–2014, the average lipid content of herring muscle decreased from 5%–6% (wet mass) to 1.5% (wet mass). Generalized linear mixed models indicated that sea water salinity and the size of the herring stock explained best the declining trend of lipid content. We estimated that the amount of the lipid storage incorporated in the spawning stock decreased by approximately 45% during the study, with respective energy content decreases. Fatty acid composition analysis revealed that herring lipids contained a high proportion of EPA (eicosapentaenoic acid; 20:5n-3) and DHA (docosahexaenoic acid; 22:6n-3), which likely originated from its main summertime prey, Limnocalanus macrurus. The results illustrate various climate change-induced processes leading to changes in the lipid content of the Baltic herring and, consequently, to changes in the energy flows of the northern Baltic ecosystem.


2020 ◽  
Author(s):  
Hojjat Asadollahpour Nanaei ◽  
Ali Esmailizadeh ◽  
Ahmad Ayatollahi Mehrgardi ◽  
Han Jianlin ◽  
Dong-Dong Wu ◽  
...  

Abstract Background Body size is considered as one of the most fundamental properties of an organism. Due to intensive breeding and artificial selection throughout the domestication history, horses exhibit striking variations for heights at withers and body sizes. Debao pony (DBP), a famous Chinese horse, is known for its small body size and lives in Guangxi mountains of southern China. In this study, we employed comparative population genomics to study the genetic basis underlying the small body size of DBP breed based on the whole genome sequencing data. To detect genomic signatures of positive selection, we applied three methods based on population comparison, fixation index (FST), cross population composite likelihood ratio (XP-CLR) and nucleotide diversity (Pi), and further analyzed the results to find genomic regions under selection for body size-related traits.Results A number of protein-coding genes with significant (P-value < 0.01) higher FST values (367 genes), XP-CLR scores (681 genes), and a lower value for nucleotide diversity (332 genes) were identified. The most significant signal of positive selection was mapped to the NELL1 gene, probably underlies the body size and development traits, and may also have independently been selected for short stature in the DBP population. In addition, some other loci on different chromosomes were identified to be potentially involved in the development of body size.Conclusions Results of our study identified some positively selected genes across the horse genome, which are possibly involved in body size traits. These novel candidate genes may be useful targets for clarifying our understanding of the molecular basis of body size and as such they should be of great interest for future research into the genetic architecture of relevant traits in horse breeding program.


2016 ◽  
Author(s):  
Johan Eklöf ◽  
Åsa Austin ◽  
Ulf Bergström ◽  
Serena Donadi ◽  
Britas D H K Eriksson ◽  
...  

Background. Organism biomass is one of the most important variables in ecological studies, making estimations of organism weight one of the most common laboratory tasks. Biomass of small macroinvertebrates is usually estimated as dry (DW) or ash-free dry weight (AFDW); a laborious and time consuming process, that often can be speeded up using easily measured and reliable proxy variables like wet/fresh weight and/or body size. Another common way of estimating AFDW - which is the most accurate but also time-consuming estimate of biologically active tissue weight - is the use of AFDW/DW ratios or conversion factors. So far, however, these ratios typically ignore the possibility that the relative weight of biologically active vs. non-active support tissue (e.g. protective exoskeleton or shell) - and therefore, also the AFDW/DW ratio - may change with body size, as previously shown for taxa like spiders, vertebrates and trees. Methods. We collected samples of aquatic, epibenthic macroinvertebrates (>1 mm) in 32 shallow bays along a 360 km stretch of the Swedish coast along the Baltic Sea; one of the largest brackish water bodies on Earth. We then estimated statistical relationships between the body size (length or height in mm), dry weight and ash-free dry weight for 14 of the most common taxa; five gastropods, three bivalves, three crustaceans and three insect larvae. Finally, we statistically estimated the potential influence of body size on the AFDW/DW ratio per taxon. Results. For most of the taxa, non-linear regression models describing the power relationship between body size and i) DW and ii) AFDW fit the data well (as indicated by low SE and high R2). Moreover, for more than half of the taxa studied (including the vast majority of the shelled molluscs), body size had a negative influence on organism AFDW/DW ratios. Discussion. The good fit of the modelled power relationships suggest that the constants reported here can be used to more quickly estimate organism dry- and ash-free dry weight based on body size, thereby freeing up considerable work resources. However, the considerable differences in constants between taxa emphasize the need for taxon-specific relationships, and the potential dangers associated with either ignoring body size or substituting relationships between taxa. The negative influence of body size on AFDW/DW ratio found in a majority of the molluscs could be caused by increasingly thicker shells with organism age, and/or spawning-induced loss of biologically active tissue in adults. Consequently, future studies utilizing AFDW/DW (and presumably also AFDW/wet weight) ratios should carefully assess the potential influence of body size to ensure more reliable estimates of organism biomass.


2011 ◽  
Vol 51 (20) ◽  
pp. 307-323 ◽  
Author(s):  
Luis Alberto Pereira

The geophilomorph centipede Pectiniunguis minutus (Demange, 1968), a little known dwarf schendylid from Gabon (Western equatorial Africa), is redescribed and illustrated based on the type material and an additional non-type specimen preserved in the collections of the Muséum national d'Histoire naturelle, Paris. P. minutus can be easily differentiated from all the other species currently assigned to the genus Pectiniunguis, by the very low number of leg-bearing segments (35 in the males, 37 or 39 in the females) and very small body size (12-16 mm in length). P. minutus is also distinguished by having ventral pore-fields on the anterior region of the body only, this character being shared by a single species of the genus, i.e., P. ascendens Pereira, Minelli & Barbieri, 1994, from the Neotropics (Brazil: State of Amazonas) with which a morphological comparison is given. Comments about other dwarf centipede species belonging to several families of the order Geophilomorpha, are also added.


2017 ◽  
Vol 13 (1) ◽  
pp. 50-58
Author(s):  
Sri Sumarmi Sri Sumarmi ◽  
Nunik Puspitasari ◽  
Soenarnatalina Melaniani

Micronutrients deficiency is prevalent among women in reproductive age, particularly in developing countries, including in Indonesia. Small body size reflects a chronic deficiency of nutrients intake. Both of those problems may correlate each other and making maternal nutrition more complicated. Brides-to be are the most important group of women in reproductive age who require better recognition, because they will become mothers. This study was to describe inter-correlation among anthropometric indices which reflected the maternal body size and several indicators of micronutrient status. A cross sectional study was conducted in selected sub-districts of Probolinggo District, East Java Province year 2012. The samples size of 115 brides-to be were randomly selected from list of brides-to be in Sub-district Office of Religious Affair. The observed variables were body weight, height, body mass index (BMI), mid upper arms circumference (MUAC), micronutrients status including concentration of hemoglobin, serum ferritin, serum retinol and serum zinc. Pearson correlation test was used to analyze data using SPSS for Window version 13.0. Result showed that the average of body weight was 47,3 kg, average stature was 150,4 cm, BMI was 20, MUAC was 25,3 cm. The average of hemoglobin level was 12,4 g/dL, serum ferritin was 50,6 g/L, serum retinol level was 1,06 mol/L, and serum Zn level was 12,9 mol/L. Statistical analisis showed significant correlation between the body weight and hemoglobin concentration (r =0,25, p = 0,01) and serum retinol (r = 0,21, p = 0,03); between BMI and hemoglobin concentration (r = 0,31, p = 0,00) and serum ferritin (r = 0,23, p = 0,03), and serum retinol (r = 0,21, p = 0,02); between MUAC and hemoglobin (r = 0,32, p = 0,00) and serum retinol (r = 0,24, p = 0,02); between hemoglobin concentration and serum ferritin concentration (r = 0,30, p = 0,00). Stature did not correlate with any indicators of micronutrient. It implies that among the indices of body size, body weight and BMI as well as MUAC are important indicators relating to iron status, and vitamin A status, but not zinc status.


Author(s):  
Helen J. Read ◽  
Henrik Enghoff

A large sample of Siphonophoridae from Brazil was studied; two morphological groups could be distinguished. Here species considered to be from the genus Columbianum Verhoeff, 1941 are examined in detail. The genus is known from Central and South America (Guatemala, Panama, Honduras, Guiana, Colombia, Peru and Brazil) and is characterised by a clear demarcation between head and rostrum in combination with long antennae, clearly surpassing the tip of the rostrum. A list of previously described species considered to belong to the genus is given; three new species are described: C. major sp. nov. has a large body size and a small head, C. nahvalr sp. nov. has a particularly pronounced domed head and a more castellated appearance to the body, C. adisi sp. nov. has a small body size and a very characteristic hind margin to the pleurites. Variation in the state of preservation of specimens hinders a diagnosis, but the examination of the accessory claw and details of the metazonital limbus and pleurite edges are helpful. Unusually for Diplopoda, the male gonopods are not very useful for identification. Ecological comments are given for each new species, one of which, C. adisi sp. nov., is from the seasonally flooded forest and appears to avoid inundation by climbing trees.


2016 ◽  
Author(s):  
Johan Eklöf ◽  
Åsa Austin ◽  
Ulf Bergström ◽  
Serena Donadi ◽  
Britas D H K Eriksson ◽  
...  

Background. Organism biomass is one of the most important variables in ecological studies, making estimations of organism weight one of the most common laboratory tasks. Biomass of small macroinvertebrates is usually estimated as dry (DW) or ash-free dry weight (AFDW); a laborious and time consuming process, that often can be speeded up using easily measured and reliable proxy variables like wet/fresh weight and/or body size. Another common way of estimating AFDW - which is the most accurate but also time-consuming estimate of biologically active tissue weight - is the use of AFDW/DW ratios or conversion factors. So far, however, these ratios typically ignore the possibility that the relative weight of biologically active vs. non-active support tissue (e.g. protective exoskeleton or shell) - and therefore, also the AFDW/DW ratio - may change with body size, as previously shown for taxa like spiders, vertebrates and trees. Methods. We collected samples of aquatic, epibenthic macroinvertebrates (>1 mm) in 32 shallow bays along a 360 km stretch of the Swedish coast along the Baltic Sea; one of the largest brackish water bodies on Earth. We then estimated statistical relationships between the body size (length or height in mm), dry weight and ash-free dry weight for 14 of the most common taxa; five gastropods, three bivalves, three crustaceans and three insect larvae. Finally, we statistically estimated the potential influence of body size on the AFDW/DW ratio per taxon. Results. For most of the taxa, non-linear regression models describing the power relationship between body size and i) DW and ii) AFDW fit the data well (as indicated by low SE and high R2). Moreover, for more than half of the taxa studied (including the vast majority of the shelled molluscs), body size had a negative influence on organism AFDW/DW ratios. Discussion. The good fit of the modelled power relationships suggest that the constants reported here can be used to more quickly estimate organism dry- and ash-free dry weight based on body size, thereby freeing up considerable work resources. However, the considerable differences in constants between taxa emphasize the need for taxon-specific relationships, and the potential dangers associated with either ignoring body size or substituting relationships between taxa. The negative influence of body size on AFDW/DW ratio found in a majority of the molluscs could be caused by increasingly thicker shells with organism age, and/or spawning-induced loss of biologically active tissue in adults. Consequently, future studies utilizing AFDW/DW (and presumably also AFDW/wet weight) ratios should carefully assess the potential influence of body size to ensure more reliable estimates of organism biomass.


Author(s):  
Alessandro Valbonesi ◽  
Graziano Di Giuseppe ◽  
Adriana Vallesi ◽  
Pierangelo Luporini

Two new Euplotes species have been isolated from cold shallow sandy sediments of the extreme Southern Chilean coasts: Euplotes foissneri sp. nov., from a low-salinity site at Puerto Natales on the Pacific coast, and Euplotes warreni sp. nov., from a marine site at Punta Arenas on the Atlantic coast. Euplotes foissneri has a medium body size (53×36 µm in vivo), a dorsal surface marked by six prominent ridges, a double dargyrome, six dorsal and two ventrolateral kineties, a buccal field extending to about 3/4 of the body length, an adoral zone composed of 28–32 membranelles, and nine fronto-ventral, five transverse and two or three caudal cirri. The bulky, hook-, horseshoe- or 3-shaped macronucleus is associated with one sub-spherical micronucleus. The central body region hosts taxonomically unidentified endosymbiotic eubacteria. Euplotes warreni has a small body size (39×27 µm in vivo), a smooth dorsal surface marked by three deep grooves, a double dargyrome, four dorsal and two ventrolateral kineties, a buccal field extending to about 2/3 of the body length, an adoral zone composed of 23–25 adoral membranelles, and nine fronto-ventral, five transverse and three caudal cirri. The macronucleus is hook- or C-shaped and associated with one spherical micronucleus. Endosymbiotic bacteria belonging to the genus Francisella reside preferentially in the anterior cell region. Both species lack the fronto-ventral cirrus numbered ‘V/2’, whereby their cirrotype-9 conforms to the so-called ‘pattern I’, which is the basic distinctive trait of the genus Euplotopsis Borror and Hill, 1995. Phylogenetic analyses of small subunit rRNA gene sequences, however, classify E. warreni into its own early branching clade and E. foissneri into a late branching clade. This indicates a polyphyletic nature and taxonomic inconsistency of the genus Euplotopsis, which was erected to include Euplotes species with cirrotype-9 pattern I.


1981 ◽  
Vol 38 (1) ◽  
pp. 25-46 ◽  
Author(s):  
D. S. Falconer ◽  
I. K. Gauld ◽  
R. C. Roberts ◽  
D. A. Williams

SUMMARYAggregation chimaeras were made from embryos of strains of mice selected for large and small body size and of unselected controls. The strains were combined in pairs marked by albino coat colour and by allo-zyme variants at the Gpi-1 locus. The proportion of cells derived from each component was scored visually in the coat melanocytes and by electrophoresis in ten other organs or tissues (blood, liver, lung, spleen, spinal cord, brain, pituitary, kidney, adrenal and testis). The object was to find out how body weight is related to cell proportions in the body as a whole and in the separate organs. Individuals varied widely in their mean cell proportions but there were significant differences between organs within individuals. Body weight was linearly related to the mean cell proportions which accounted for most, or possibly all, of the chimaeric variance of body weight. No one of the organs studied could be identified as being solely responsible for growth control, or as having a predominant influence on growth. The weights of some organs were probably influenced to a small extent by their own cell proportions independently of the individual's mean, but the differences of body weight were too great to be accounted for by the summation of localized effects on organs. The mean cell proportion, averaged over individuals, was close to 50%, proving that there was no tendency for cells from the larger component to outgrow those from the smaller. It is concluded that growth control must be systemic, but it was not possible to decide whether the systemic effect comes from some particular organ not studied, or is in some undefined way the consequence of the cell proportions in the body as a whole. There was some evidence, though it was inconclusive, that chimaeras show ‘heterosis’ for body weight.


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