scholarly journals Symbiosis increases population size and buffers environmental fluctuations in a physiologically-structured model parameterized for thyasirid bivalves

2021 ◽  
Author(s):  
Joany Mariño ◽  
Suzanne C Dufour ◽  
Amy Hurford
Keyword(s):  
Population Dynamics ◽  
Community Dynamics ◽  
Resource Limitation ◽  
Symbiotic Bacteria ◽  
Free Living ◽  
Additional Energy ◽  
Structured Population Model ◽  
Dynamic Energy Budget Theory ◽  
Budget Theory ◽  
Living Bacteria

Symbioses whereby one partner provisions a nutritional resource to the other may alter energy allocation towards reproduction and survival in the recipient partner, potentially impacting population dynamics. Asymbiotic thyasirid bivalves feed predominantly on free-living bacteria, which fluctuate in abundance due to seasonality-driven temperature variations. Symbiotic thyasirids are mixotrophs, gaining nutrients from free-living bacteria and symbiotic bacteria that they host on their enlarged gills. Symbiotic bacteria may function as an additional energy reserve for thyasirids, allowing the hosts to allocate more energy to reproduction. We hypothesize that, for symbiotic thyasirids, the symbionts are a nutritional source that mitigates resource limitation. Using Dynamic Energy Budget theory, we built a physiologically-structured population model assuming equal mortality rates in both species. We find that without seasonal fluctuations, symbiotic thyasirids have higher abundances than asymbiotic thyasirids since the symbionts increase reproduction. Both species have similar population sizes in fluctuating environments, suggesting different adaptations to seasonality: asymbiotic thyasirids have adapted their physiology, while symbiotic thyasirids have adapted through mixotrophy. Our results highlight the significance of linking individual energetics and life-history traits to population dynamics and are the first step towards understanding the role of symbioses in population and community dynamics.

Predicting Population Dynamics from the Properties of Individuals: A Cross-Level Test of Dynamic Energy Budget Theory

2013 ◽  
Vol 181 (4) ◽  
pp. 506-519 ◽  
Author(s):  
Benjamin T. Martin ◽  
Tjalling Jager ◽  
Roger M. Nisbet ◽  
Thomas G. Preuss ◽  
Volker Grimm
Keyword(s):  
Population Dynamics ◽  
Energy Budget ◽  
Dynamic Energy Budget ◽  
Dynamic Energy Budget Theory ◽  
Budget Theory

scholarly journals Symbiotic Bacteria in Gills and Guts of Chinese Mitten Crab (Eriocheir sinensis) Differ from the Free-Living Bacteria in Water

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0148135 ◽  
Author(s):  
Meiling Zhang ◽  
Yuhong Sun ◽  
Liqiao Chen ◽  
Chunfang Cai ◽  
Fang Qiao ◽  
...  
Keyword(s):  
Eriocheir Sinensis ◽  
Symbiotic Bacteria ◽  
Chinese Mitten Crab ◽  
Free Living ◽  
Mitten Crab ◽  
Living Bacteria

scholarly journals Opening a next-generation black box: ecological trends for hundreds of species-like taxa uncovered within a single bacterial >99% 16S rRNA operational taxonomic unit

2021 ◽  
Author(s):  
Martin Hahn ◽  
Andrea Huemer ◽  
Alexandra Pitt ◽  
Matthias Hoetzinger
Keyword(s):  
16S Rrna ◽  
Sequence Similarity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Taxon Richness ◽  
Large Set ◽  
Free Living ◽  
Environmental Distribution ◽  
Living Bacteria

Current knowledge on environmental distribution and taxon richness of free-living bacteria is mainly based on cultivation-independent investigations employing 16S rRNA gene sequencing methods. Yet, 16S rRNA genes are evolutionarily rather conserved, resulting in limited taxonomic and ecological resolutions provided by this marker. We used a faster evolving protein-encoding marker to reveal ecological patterns hidden within a single OTU defined by >99% 16S rRNA sequence similarity. The studied taxon, subcluster PnecC of the genus Polynucleobacter, represents a ubiquitous group of planktonic freshwater bacteria with cosmopolitan distribution, which is very frequently detected by diversity surveys of freshwater systems. Based on genome taxonomy and a large set of genome sequences, a sequence similarity threshold for delineation of species-like taxa could be established. In total, 600 species-like taxa were detected in 99 freshwater habitats scattered across three regions representing a latitudinal range of 3400 km (42°N to 71°N) and a pH gradient of 4.2 to 8.6. Besides the unexpectedly high richness, the increased taxonomic resolution revealed structuring of Polynucleobacter communities by a couple of macroecological trends, which was previously only demonstrated for phylogenetically much broader groups of bacteria. A unexpected pattern was the almost complete compositional separation of Polynucleobacter communities of Ca-rich and Ca-poor habitats, which strongly resembled the vicariance of plant species on silicate and limestone soils. The presented new cultivation-independent approach opened a window to an incredible, previously unseen diversity, and enables investigations aiming on deeper understanding of how environmental conditions shape bacterial communities and drive evolution of free-living bacteria.

Symbiotic bacteria of helminths: what role may they play in ecosystems under anthropogenic stress?

2016 ◽  
Vol 90 (6) ◽  
pp. 647-657 ◽  
Author(s):  
N.J. Morley
Keyword(s):  
Climate Change ◽  
Environmental Stress ◽  
Bacterial Communities ◽  
Bacterial Species ◽  
Symbiotic Bacteria ◽  
Anthropogenic Pressure ◽  
Anthropogenic Stress ◽  
Similar Function ◽  
Free Living ◽  
Terrestrial Habitats

AbstractSymbiotic bacteria are a common feature of many animals, particularly invertebrates, from both aquatic and terrestrial habitats. These bacteria have increasingly been recognized as performing an important role in maintaining invertebrate health. Both ecto- and endoparasitic helminths have also been found to harbour a range of bacterial species which provide a similar function. The part symbiotic bacteria play in sustaining homeostasis of free-living invertebrates exposed to anthropogenic pressure (climate change, pollution), and the consequences to invertebrate populations when their symbionts succumb to poor environmental conditions, are increasingly important areas of research. Helminths are also susceptible to environmental stress and their symbiotic bacteria may be a key aspect of their responses to deteriorating conditions. This article summarizes the ecophysiological relationship helminths have with symbiotic bacteria and the role they play in maintaining a healthy parasite and the relevance of specific changes that occur in free-living invertebrate–bacteria interactions under anthropogenic pressure to helminths and their bacterial communities. It also discusses the importance of understanding the mechanistic sensitivity of helminth–bacteria relationships to environmental stress for comprehending the responses of parasites to challenging conditions.

scholarly journals Designer endosymbionts: Converting free-living bacteria into organelles

2020 ◽  
Vol 24 ◽  
pp. 41-50
Author(s):  
Rebecca S. Meaney ◽  
Samir Hamadache ◽  
Maximillian P.M. Soltysiak ◽  
Bogumil J. Karas
Keyword(s):  
Free Living ◽  
Living Bacteria
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