scholarly journals Dynamics of Calanus Copepodite Structure during Little Auks’ Breeding Seasons in Two Different Svalbard Locations

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1405
Author(s):  
Kaja Balazy ◽  
Emilia Trudnowska ◽  
Katarzyna Błachowiak-Samołyk
Keyword(s):  
Body Size ◽  
Zooplankton Community ◽  
Atlantic Water ◽  
The Body ◽  
Trophic Levels ◽  
Calanus Finmarchicus ◽  
Relative Role ◽  
Little Auk ◽  
Diving Depth ◽  
Over Time

Populations dynamics of key zooplankton species in the European Arctic, Calanus finmarchicus and Calanus glacialis (hereafter defined as Calanus) may be sensitive to climate changes, which in turn is of great importance for higher trophic levels. The aim of this study was to investigate the complete copepodite structure and dynamics of Calanus populations in terms of body size, phenology and their relative role in the zooplankton community over time in different hydrographic conditions (two fjords on the West Spitsbergen Shelf, cold Hornsund vs. warm Kongsfjorden), from the perspective of their planktivorous predator, the little auk. High-resolution zooplankton measurements (taken by nets and a laser optical plankton counter) were adapted to the timing of bird’s breeding in the 2015 and 2016 summer seasons, and to their maximal diving depth (≤50 m). In Hornsund, the share of the Calanus in zooplankton community was greater and the copepodite structure was progressively older over time, matching the little auks timing. The importance of Calanus was much lower in Kongsfjorden, as represented mainly by younger copepodites, presumably due to the Atlantic water advections, thus making this area a less favourable feeding ground. Our results highlight the need for further studies on the match/mismatch between Calanus and little auks, because the observed trend of altered age structure towards a domination of young copepodites and the body size reduction of Calanus associated with higher seawater temperatures may result in insufficient food availability for these seabirds in the future.

scholarly journals Terrestrial evidence for the Lilliput effect across the Cretaceous-Paleogene (K-Pg) boundary

2017 ◽  
Author(s):  
Logan Wiest ◽  
William E. Lukens ◽  
Daniel J. Peppe ◽  
Steven G. Driese ◽  
Jack Tubbs
Keyword(s):  
Body Size ◽  
Taxonomic Composition ◽  
The Body ◽  
Trophic Levels ◽  
Size Change ◽  
Big Bend National Park ◽  
Big Bend ◽  
Marine Realm ◽  
Anomalous Shift ◽  
Community Shifts

Recent research has demonstrated that the Lilliput effect (reduction of body size in response to a mass extinction) affected all trophic levels in the marine realm following the Cretaceous-Paleogene (K-Pg) event. However, it is unclear if this size change was strictly a marine signal, or a global phenomenon that also affected continental ecosystems. Herein we present the results of an ichnological proxy for body size of soil-dwelling insects across the K-Pg boundary in Big Bend National Park, Texas, U.S.A. Quantitative efforts focused on Naktodemasis isp., which are characterized as unbranching burrows composed of ellipsoidal packets of backfill menisci. These traces were likely produced by beetle larvae or cicada nymphs based on previous comparison with structures generated in modern soils and laboratory experiments. As an approximation for the body size of the subterranean insects, this dataset indicates that a smaller Naktodemasis diameter (DN) is statistically correlated (α < 0.05) with several edaphic factors including poor drainage and weak development (Entisols). Additionally, the DN in strata immediately superjacent to the highest Cretaceous-specific taxa is smaller by 23% (5.6 ± 1.8 mm) in comparison to DN within the subjacent Cretaceous interval (7.3 ± 2.7 mm). This abrupt shift occurs in a well-drained Inceptisol, and cannot be attributed to facies changes, drainage, or paleosol maturity. Furthermore, a reduced DN (6.6 ± 2.3 mm) persists above this anomalous shift for at least 20 stratigraphic meters within chron 29r. The cause for this negative response in body size within soil-dwelling biota may be attributed to plant-community shifts in taxonomic composition and ecological strategies, which would have caused fundamental alterations to the diet of the herbivorous, subterranean insects. This study provides empirical evidence that the Lilliput effect was not restricted to marine environments during the aftermath of the K-Pg event.

scholarly journals Interspecific hierarchies from aggressiveness and body size among the invasive alien hornet, Vespa velutina nigrithorax, and five native hornets in South Korea

2019 ◽  
Author(s):  
Ohseok Kwon ◽  
Moon Bo Choi
Keyword(s):  
Body Size ◽  
South Korea ◽  
The Body ◽  
High Rate ◽  
Aggressive Behaviors ◽  
Vespa Velutina ◽  
High Incidence ◽  
Spreading Rates ◽  
Over Time

AbstractThe range of the invasive alien hornet, Vespa velutina nigrithorax, has been continuously expanding since its invasion of Korea in 2003. Here, we compared the aggressive behaviors and body size of V. velutina nigrithorax with five native hornet species to identify the interspecific hierarchies that contributes to the spread of this species. Aggressive behaviors were classified into 11 categories and each interaction was scored as a win, loss, or tie. As a result, V. velutina was superior to V. simillima in 153 fights where V. velutina won 71% and showed a high incidence of threatening behavior. V. mandarinia outperformed V. velutina in 104 fights where V. mandarinia won 91% and grappling behavior was common. V. analis was superior to V. velutina in 67 fights where V. analis won 76% and showed a high amount of threatening behavior. V. crabro was superior to V. velutina in 93 fights where V. crabro won 73% and showed a high rate of threatening behavior. V. dybowskii was superior to V. velutina in 132 fights where V. dybowskii won 91%, and showed a high rate of threatening and grappling behaviors. The body size of V. velutina was larger than V. simillima (although not statistically significant) and smaller than all other Vespa species. Therefore, according to the results of this study, the low interspecific hierarchies of V. velutina seems to be a major cause of slower spreading rates than it has shown in Europe. However, over time, its density has gradually increased within the forest, in which it seems to be overcoming its disadvantages and expanding its range, possibly as large colonies and good flying abilities make it easier to secure food.

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

scholarly journals Habitat loss and fragmentation increase realized predator-prey body size ratios

2018 ◽  
Author(s):  
Jasmijn Hillaert ◽  
Martijn L. Vandegehuchte ◽  
Thomas Hovestadt ◽  
Dries Bonte
Keyword(s):  
Body Size ◽  
Habitat Fragmentation ◽  
Food Web ◽  
Habitat Loss ◽  
The Body ◽  
Trophic Levels ◽  
Top Down ◽  
Habitat Loss And Fragmentation ◽  
Gap Crossing ◽  
Primary Consumers

AbstractIn the absence of predators, habitat fragmentation favors large body sizes in primary consumers with informed movement due to their high gap-crossing ability. However, the body size of primary consumers is not only shaped by such bottom-up effects, but also by top-down effects as predators prefer prey of a certain size. Therefore, higher trophic levels should be taken into consideration when studying the effect of habitat loss and fragmentation on size distributions of herbivores.We built a model to study the effect of habitat loss and fragmentation within a simple food web consisting of (i) a basal resource that is consumed by (ii) a herbivore that in turn is consumed by (iii) a predator. Our results highlight that predation may result in local accumulation of the resource via top-down control of the herbivore. As such, the temporal and spatial variation of the resource distribution is increased, selecting for increased herbivore movement. This results in selection of larger herbivores than in the scenario without predator. As predators cause herbivores to be intrinsically much larger than the optimal sizes selected by habitat fragmentation in the absence of predators, habitat fragmentation is no longer a driver of herbivore size. However, there is selection for increased predator size with habitat fragmentation as herbivores become less abundant, favoring gap-crossing ability of the predator. Since herbivore and predator body size respond differently to habitat loss and fragmentation, realized predator-herbivore body size ratios increase along this fragmentation gradient. Our model predicts the dominance of top-down forces in regulating body size selection in food webs and helps to understand how habitat destruction and fragmentation affect overall food web structure.

scholarly journals Body-size trends of the extinct giant sharkCarcharocles megalodon: a deep-time perspective on marine apex predators

Paleobiology ◽  
2015 ◽  
Vol 41 (3) ◽  
pp. 479-490 ◽  
Author(s):  
Catalina Pimiento ◽  
Meghan A. Balk
Keyword(s):  
Body Size ◽  
Time Perspective ◽  
Selective Pressure ◽  
The Body ◽  
Shark Species ◽  
Apex Predators ◽  
Deep Time ◽  
Geologic Time ◽  
Marine Predators ◽  
Over Time

AbstractThe extinct sharkCarcharocles megalodonis one of the largest marine apex predators ever to exist. Nonetheless, little is known about its body-size variations through time and space. Here, we studied the body-size trends ofC. megalodonthrough its temporal and geographic range to better understand its ecology and evolution. Given that this species was the last of the megatooth lineage, a group of species that shows a purported size increase through time, we hypothesized thatC. megalodonalso displayed this trend, increasing in size over time and reaching its largest size prior to extinction. We found thatC. megalodonbody-size distribution was left-skewed (suggesting a long-term selective pressure favoring larger individuals), and presented significant geographic variation (possibly as a result of the heterogeneous ecological constraints of this cosmopolitan species) over geologic time. Finally, we found that stasis was the general mode of size evolution ofC. megalodon(i.e., no net changes over time), contrasting with the trends of the megatooth lineage and our hypothesis. Given thatC. megalodonis a relatively long-lived species with a widely distributed fossil record, we further used this study system to provide a deep-time perspective to the understanding of the body-size trends of marine apex predators. For instance, our results suggest that (1) a selective pressure in predatory sharks for consuming a broader range of prey may favor larger individuals and produce left-skewed distributions on a geologic time scale; (2) body-size variations in cosmopolitan apex marine predators may depend on their interactions with geographically discrete communities; and (3) the inherent characteristics of shark species can produce stable sizes over geologic time, regardless of the size trends of their lineages.

scholarly journals Different increase rate in body mass of two marten species due to climate warming potentially reinforces interspecific competition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Wereszczuk ◽  
Tim R. Hofmeester ◽  
Alexander Csanády ◽  
Tomislav Dumić ◽  
Morten Elmeros ◽  
...  
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Geographic Range ◽  
The Body ◽  
Stone Marten ◽  
Pine Marten ◽  
Adaptation To Climate Change ◽  
Geographical Patterns ◽  
Pine Martens ◽  
Over Time

AbstractMany species show spatial variation in body size, often associated with climatic patterns. Studying species with contrasting geographical patterns related to climate might help elucidate the role of different drivers. We analysed changes in the body mass of two sympatric medium-sized carnivores—pine marten (Martes martes) and stone marten (Martes foina)—across Europe over 59 years. The body mass of pine marten increased with decreasing latitude, whereas stone marten body mass varied in a more complex pattern across its geographic range. Over time, the average body mass of pine martens increased by 255 g (24%), while stone marten by 86 g (6%). The greatest increase of body mass along both martens’ geographic range was observed in central and southern Europe, where both species occur in sympatry. The body mass increase slowed down over time, especially in allopatric regions. The average pine/stone marten body mass ratio increased from 0.87 in 1960 to 0.99 in 2019, potentially strengthening the competition between them. Thus, a differential response in body size to several drivers over time might have led to an adaptive advantage for pine martens. This highlights the importance of considering different responses among interacting species when studying animal adaptation to climate change.

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.

The Body Size of Headstarted and Wild Juvenile European Pond Turtles (Emys orbicularis)

2017 ◽  
Vol 25 (2) ◽  
pp. 161
Author(s):  
Sławomir Mitrus ◽  
Bartłomiej Najbar ◽  
Adam Kotowicz ◽  
Anna Najbar
Keyword(s):  
Body Size ◽  
The Body ◽  
Emys Orbicularis

scholarly journals The prevalence of underweight in 9–10-year-old schoolchildren in Liverpool: 1998–2006

2009 ◽  
Vol 12 (7) ◽  
pp. 953-956 ◽  
Author(s):  
Lynne M Boddy ◽  
Allan F Hackett ◽  
Gareth Stratton
Keyword(s):  
Mass Spectrum ◽  
Body Mass ◽  
The Body ◽  
Fitness Testing ◽  
Policy Makers ◽  
Substantial Problem ◽  
Prevalence Of Obesity ◽  
Grade 3 ◽  
The City ◽  
Over Time

AbstractObjectiveTo estimate the prevalence of underweight between 1998 and 2006 in Liverpool schoolchildren aged 9–10 years using recently published underweight cut-off points.Design and settingStature and body mass data collected at the LiverpoolSportsLinx project’s fitness testing sessions were used to calculate BMI.SubjectsData were available on 26 782 (n13 637 boys, 13 145 girls) participants.ResultsOverall underweight declined in boys from 10·3 % in 1998–1999 to 6·9 % in 2005–2006, and all sub-classifications of underweight declined, in particular grade 3 underweight, with the most recent prevalence being 0·1 %. In girls, the prevalence of underweight declined from 10·8 % in 1998–1999 to 7·5 % in 2005–2006. The prevalence of all grades of underweight was higher in girls than in boys. Underweight showed a fluctuating pattern across all grades over time for boys and girls, and overall prevalence in 2005–2006 represents over 200 children across the city.ConclusionsUnderweight may have reduced slightly from baseline, but remains a substantial problem in Liverpool, with the prevalence of overall underweight being relatively similar to the prevalence of obesity. The present study highlights the requirement for policy makers and funders to consider both ends of the body mass spectrum when fixing priorities in child health.

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