scholarly journals Size variation of morphological traits in Bosmina freyi and its relation with environmental variables in a tropical eutrophic reservoir

Bionatura ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 1763-1769
Author(s):  
Yury Catalina López-Cardona ◽  
Edison Parra-García ◽  
Jaime Palacio-Baena ◽  
Silvia Lucía Villabona-González
Keyword(s):  
Body Size ◽  
Environmental Variables ◽  
Morphological Traits ◽  
Size Structure ◽  
Small Body ◽  
Size Variation ◽  
Zooplankton Community ◽  
The Body ◽  
Zooplankton Community Structure ◽  
Heterogeneous Distribution

We assessed the size variation of morphological traits in Bosmina freyi regarding changes in environmental variables, the biomass of invertebrate predators, and algal food availability in two depths of the photic zone, the riverine zone, and near the dam zone (lacustrine zone) in The Riogrande II reservoir. In 200 individuals of B. freyi, using the software TpsDig2 we measured the body size, mucron and antennule lengths, and the antennule aperture percentage. Using the Mann-Whitney U test, we assessed the differences between these traits considering the zones and the photic depths; however, we used a canonical discriminant analysis with morphologic traits and environmental variables. Measured morphological traits showed a heterogeneous distribution between sampled zones and depths (p < 0.05). The highest values mucron and antennule lengths and the smallest antennule aperture angle were observed on small body size individuals, associated with physical, chemical, and biological characteristics in the riverine zone and the subsurface. Size structure distribution in B. freyi was related to changes in water temperature, trophic state, depredation, availability, and quality of food, of which implications related to the zooplankton community structure, predator-prey relations, and energy flow in the reservoir.

Body Size and Feeding Ecology as Alternatives to Taxonomy for the Study of Limnetic Zooplankton Community Structure

1979 ◽  
Vol 36 (11) ◽  
pp. 1354-1363 ◽  
Author(s):  
W. Gary Sprules ◽  
L. Blair Holtby
Keyword(s):  
Image Analysis ◽  
Community Structure ◽  
Body Size ◽  
Feeding Ecology ◽  
Zooplankton Community ◽  
The Body ◽  
Size Spectrum ◽  
Zooplankton Community Structure ◽  
Flow Through ◽  
Zooplankton Communities

Three different characterizations of limnetic zooplankton communities from lakes of the Bruce Peninsula, Ontario are compared with respect to their usefulness in limnological studies: a conventional taxonomic one, one based on the body size and feeding ecology of the organisms, and one based on image analysis of the particle size spectrum. In comparison with the taxonomic characterization, the ecological and image analysis characterizations reflect zooplankton community features which are more closely related to the efficiency and nature of energy flow through pelagic ecosystems. Furthermore, it is demonstrated that these features have stronger statistical relations to morphometric and hydrological properties of lakes. The ecological and image analyses are thus not only more useful in studies seeking to make predictions about lake function from lake type but actually require less time, money and expertise in the acquisition of zooplankton data. In comparisons of zooplankton communities from the disparate faunal regions of the Bruce Peninsula, Ontario and southeast Asia, particularly Sri Lanka, more useful functional insights emerge from a body size-feeding ecology characterization than from a taxonomically based one. Key words: community structure, image analysis, Bruce Peninsula, tropical zooplankton, zoogeography, multivariate analysis

Is body size variation in the platypus (Ornithorhynchus anatinus) associated with environmental variables?

2011 ◽  
Vol 59 (4) ◽  
pp. 201 ◽  
Author(s):  
Elise Furlan ◽  
J. Griffiths ◽  
N. Gust ◽  
R. Armistead ◽  
P. Mitrovski ◽  
...  
Keyword(s):  
Body Size ◽  
Environmental Variables ◽  
Size Variation ◽  
The Body ◽  
Body Size Variation ◽  
Temperature Regimes ◽  
Ornithorhynchus Anatinus ◽  
Eastern Australia ◽  
Lower Temperature ◽  
Latitudinal Range

The body size of the platypus (Ornithorhynchus anatinus) is known to vary across both its latitudinal range and relatively short geographic distances. Here we consider how variation in platypus length and weight associates with environmental variables throughout the species’ range. Based on data from over 800 individuals, a Bergmann’s cline (increased body size in regions of lower temperature) was detected across the species latitudinal range. The opposite association, however, was present at smaller scales when comparing platypus body size and temperature within southern mainland Australia, or within an individual river basin. Temperature regimes alone clearly did not dictate body size in platypuses, although disentangling the effects of different climatic variables on body size variation was difficult because of correlations amongst variables. Nevertheless, within suitable platypus habitat in south-eastern Australia, areas of relatively lower rainfall and higher temperatures were typically associated with larger-bodied platypuses. The potential benefits to larger-bodied animals living under these conditions are explored, including consideration of variation in energy expenditure and food availability. Assuming these associations with environmental variables are biologically significant, a shift in platypus body size is anticipated in the future with predicted changes in climate.

scholarly journals Independent evolution towards larger body size in the distinctive Faroe Island mice

2021 ◽  
Author(s):  
Ricardo Wilches ◽  
William H Beluch ◽  
Ellen McConnell ◽  
Diethard Tautz ◽  
Yingguang Frank Chan
Keyword(s):  
Body Size ◽  
Meta Analysis ◽  
Small Body ◽  
Laboratory Mouse ◽  
Large Body ◽  
Natural Populations ◽  
Size Variation ◽  
Phenotypic Traits ◽  
Island Population ◽  
Multiple Loci

Abstract Most phenotypic traits in nature involve the collective action of many genes. Traits that evolve repeatedly are particularly useful for understanding how selection may act on changing trait values. In mice, large body size has evolved repeatedly on islands and under artificial selection in the laboratory. Identifying the loci and genes involved in this process may shed light on the evolution of complex, polygenic traits. Here, we have mapped the genetic basis of body size variation by making a genetic cross between mice from the Faroe Islands, which are among the largest and most distinctive natural populations of mice in the world, and a laboratory mouse strain selected for small body size, SM/J. Using this F2 intercross of 841 animals, we have identified 111 loci controlling various aspects of body size, weight and growth hormone levels. By comparing against other studies, including the use of a joint meta-analysis, we found that the loci involved in the evolution of large size in the Faroese mice were largely independent from those of a different island population or other laboratory strains. We hypothesize that colonization bottleneck, historical hybridization, or the redundancy between multiple loci have resulted in the Faroese mice achieving an outwardly similar phenotype through a distinct evolutionary path.

scholarly journals Evolution of body size in anteaters and sloths (Xenarthra, Pilosa): phylogeny, metabolism, diet and substrate preferences

2015 ◽  
Vol 106 (4) ◽  
pp. 289-301 ◽  
Author(s):  
N. Toledo ◽  
M.S. Bargo ◽  
S.F. Vizcaíno ◽  
G. De Iuliis ◽  
F. Pujos
Keyword(s):  
Body Size ◽  
Fossil Record ◽  
Dietary Habits ◽  
Decomposition Analysis ◽  
Size Variation ◽  
The Body ◽  
Phylogenetic Pattern ◽  
Substrate Preferences ◽  
Size Evolution ◽  
Main Factor

ABSTRACTPilosa include anteaters (Vermilingua) and sloths (Folivora). Modern tree sloths are represented by two genera, Bradypus and Choloepus (both around 4–6 kg), whereas the fossil record is very diverse, with approximately 90 genera ranging in age from the Oligocene to the early Holocene. Fossil sloths include four main clades, Megalonychidae, Megatheriidae, Nothrotheriidae, and Mylodontidae, ranging in size from tens of kilograms to several tons. Modern Vermilingua are represented by three genera, Cyclopes, Tamandua and Myrmecophaga, with a size range from 0.25 kg to about 30 kg, and their fossil record is scarce and fragmentary. The dependence of the body size on phylogenetic pattern of Pilosa is analysed here, according to current cladistic hypotheses. Orthonormal decomposition analysis and Abouheif C-mean were performed. Statistics were significantly different from the null-hypothesis, supporting the hypothesis that body size variation correlates with the phylogenetic pattern. Most of the correlation is concentrated within Vermilingua, and less within Mylodontidae, Megatheriidae, Nothrotheriidae and Megalonychidae. Influence of basal metabolic rate (BMR), dietary habits and substrate preference is discussed. In anteaters, specialised insectivory is proposed as the primary constraint on body size evolution. In the case of sloths, mylodontids, megatheriids and nothrotheriids show increasing body size through time; whereas megalonychids retain a wider diversity of sizes. Interplay between BMR and dietary habits appears to be the main factor in shaping evolution of sloth body size.

scholarly journals Evidence for benthic body size miniaturization in the deep sea

2006 ◽  
Vol 86 (6) ◽  
pp. 1339-1345 ◽  
Author(s):  
Janne I. Kaariainen ◽  
Brian J. Bett
Keyword(s):  
Body Size ◽  
Deep Sea ◽  
Size Structure ◽  
Size Class ◽  
The Body ◽  
Significant Shift ◽  
Individual Biomass ◽  
Wet Weight ◽  
Accumulation Curves ◽  
Average Individual

The benthic body size miniaturization hypothesis states that deep-sea communities are dominated by organisms of smaller body size, although some field studies have produced contradictory results. Using appropriate sample sets, this study tests this hypothesis by contrasting the benthic communities of the Fladen Ground (North Sea, 150 m) and the Faroe–Shetland Channel (1600 m). Samples were collected for large (500 μm) and small macrofauna (250–355 μm), meiofauna (45 μm) as well as an intermediate sized ‘mesofauna’ (180 μm) to ensure comprehensive coverage of the full meio- and macro-faunal body size-range. The body size structure of the benthos was compared using two methods. The more widely used average individual biomass method involves dividing the total sample biomass by sample abundance. Additionally, body size accumulation curves were constructed by assigning all specimens into a logarithmic size-class and then plotting the cumulative percentage of individuals present in each size-class. The results seem to support the hypothesis that the deep-sea environment is a small organism habitat. Although these findings only represent two locations, the overall body size accumulation curves clearly display a statistically significant shift towards smaller body sizes at the deeper site. The magnitude of the effect is appreciable with median metazoan body size reducing from 14.3 μg wet weight in the Fladen Ground to 3.8 μg wet weight in the Faroe–Shetland Channel. The average individual biomass measurements are shown to be of limited value and can lead to potentially misleading conclusions if the underlying size structure is not analysed in detail.

scholarly journals Body Size Differences between Foraging and Intranidal Workers of the Monomorphic Ant Lasius niger

Insects ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 433
Author(s):  
Mateusz Okrutniak ◽  
Bartosz Rom ◽  
Filip Turza ◽  
Irena M. Grześ
Keyword(s):  
Body Size ◽  
Field Experiment ◽  
Important Determinant ◽  
Size Variation ◽  
Division Of Labour ◽  
The Body ◽  
Food Type ◽  
Lasius Niger ◽  
Worker Size ◽  
Body Sizes

The association between the division of labour and worker body size of ants is typical for species that maintain physical castes. Some studies showed that this phenomenon can be also observed in the absence of distinct morphological subcastes among workers. However, the general and consistent patterns in the size-based division of labour in monomorphic ants are largely unidentified. In this study, we performed a field experiment to investigate the link between worker body size and the division of labour of the ant Lasius niger (Linnaeus, 1758), which displays limited worker size variation. We demonstrated that the body size of workers exploring tuna baits is slightly but significantly smaller than the size of workers located in the upper parts of the nest. Comparing the present results with existing studies, large workers do not seem to be dedicated to work outside the nest. We suggest that monomorphic workers of certain body sizes are flexible in the choice of task they perform, and food type may be the important determinant of this choice.

scholarly journals Notes on variation in the baculum of Martes foina from Czech Silesia, Czech Republic (Carnivora: Mustelidae)

2016 ◽  
Vol 47 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Alexander Čanády ◽  
Anna Onderková
Keyword(s):  
Czech Republic ◽  
Morphological Traits ◽  
Size Variation ◽  
The Body ◽  
Descriptive Statistics ◽  
Strong Positive Correlation ◽  
Stone Marten ◽  
Martes Foina ◽  
North Eastern ◽  
Quantitative Characteristics

In this study we investigated variation in the baculum of the stone marten Martes foina from the Czech part of Silesia (north-eastern Czech Republic). The aim of this study was to assess quantitative characteristics of the baculum size, relationships between measurements and description of the variability in baculum morphology. The study presents the morphological variation in six dimensional traits of the baculum based on an analysis of 15 specimens collected in the vicinity of Opava and deposited at the Šariš Museum Bardejov (Slovakia). The descriptive statistics revealed size variation of the bacula, while the statictic analysis (PCA) showed a strong positive correlation between morphological traits of the body and baculum.

scholarly journals Comparative population genomic analysis uncovers novel genomic footprints and genes associated with small body size in Chinese pony

2020 ◽  
Author(s):  
Hojjat Asadollahpour Nanaei ◽  
Ali Esmailizadeh ◽  
Ahmad Ayatollahi Mehrgardi ◽  
Han Jianlin ◽  
Dong-Dong Wu ◽  
...  
Keyword(s):  
Body Size ◽  
Positive Selection ◽  
Nucleotide Diversity ◽  
Population Genomics ◽  
Small Body ◽  
Composite Likelihood ◽  
The Body ◽  
Fixation Index ◽  
Small Body Size ◽  
Comparative Population

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.

Zooplankton Community Structure in Hardwater Hypertrophic Lakes of Alberta

1993 ◽  
Vol 27 (7-8) ◽  
pp. 353-361 ◽  
Author(s):  
B. Pinel-Alloul
Keyword(s):  
Phosphorus Content ◽  
Size Structure ◽  
Zooplankton Community ◽  
Zooplankton Biomass ◽  
Western Canada ◽  
Zooplankton Abundance ◽  
Lime Treatment ◽  
Eutrophic Lakes ◽  
Size Spectra ◽  
Zooplankton Community Structure

Excessive concentrations of phosphorus are a common feature of hardwater eutrophic lakes in western Canada. Preliminary experimental lime treatment showed that this approach had a great potential to reduce phosphorus content and algal biomass. Therefore, two pairs of experimental and reference lakes were selected for a whole lake lime treatment and monitored for a full year prior to manipulation. This study presents the composition and size structure of the Zooplankton community of the lakes before treatment in order to assess the natural summer and inter-lake variations. Before lime treatment, seasonal means of total Zooplankton abundance and biomass ranged from 17 ± 8 to 127 ± 84 ind. L−1 and from 4 ± 2 to 138 ± 236 mg m−3, respectively. The two experimental lakes (Halftnoon and Lofty) were the richest in Zooplankton while the references lakes (Crooked and Jenkins) were the poorest. A total of 30 Zooplankton species (17 rotifers, 2 calanoids, 4 cyclopoids and 7 cladocerans) were recorded as well as 3 chaoborid species. The composition and size structure of Zooplankton varied between lakes and dates. Rotifers accounted for the majority of Zooplankton abundances (59-91%) while Cladocera (78-99%) or Copepoda (74%) in Crooked lake formed most of the Zooplankton biomass. Summer variations of the Zooplankton groups were described along with changes in size spectra. The temporal variation and the inter-lake differences in Zooplankton structure were discussed in relation to trophy, fish and invertebrate predation, and cyanophyte interactions.

Testing Rensch’s rule in Acanthoscelides macrophthalmus, a seed-feeding beetle infesting Leucaena leucocephala plants

2019 ◽  
Vol 97 (4) ◽  
pp. 304-311
Author(s):  
M.N. Rossi ◽  
E.B. Haga
Keyword(s):  
Body Size ◽  
Leucaena Leucocephala ◽  
Morphological Traits ◽  
Genetic Basis ◽  
Sexual Size Dimorphism ◽  
The Body ◽  
Rensch’S Rule ◽  
Size Dimorphism ◽  
Rensch's Rule ◽  
Males And Females

Rensch’s rule states that males vary more in size than females when body size increases. The main cause of Rensch’s rule has been credited to sexual selection. However, different degrees of plasticity between the sexes have also been proven to be useful for describing variations in sexual size dimorphism, particularly within an intraspecific context. For insects, in general, this rule has rarely been tested within species. Here, we tested whether Acanthoscelides macrophthalmus (Schaeffer, 1907) (Coleoptera: Chrysomelidae: Bruchinae) followed Rensch’s rule when individuals emerged from seeds immediately after fruit collection and when they were reared for one generation, by measuring three morphological traits. Rensch’s rule was not followed for any of the morphological traits. Variations in body size were similar in males and females for bruchines that first emerged from seeds and for those that were reared for one generation. These findings suggest that environmental conditions (e.g., temperature, humidity, and seasonality) are unlikely to drive differential plasticity in males and females of this seed-feeding beetle. It is possible that changes in the body size of A. macrophthalmus have a genetic basis. However, regardless of whether variations in body size have a genetic basis, our findings provide no support for Rensch’s rule.

Sign in / Sign up

Export Citation Format

Share Document