scholarly journals Ecological roles of the parasitic phytomyxids (plasmodiophorids) in marine ecosystems - a review

2011 ◽  
Vol 62 (4) ◽  
pp. 365 ◽  
Author(s):  
Sigrid Neuhauser ◽  
Martin Kirchmair ◽  
Frank H. Gleason
Keyword(s):  
Organic Matter ◽  
Reproductive Success ◽  
Food Webs ◽  
Marine Ecosystems ◽  
Freshwater Ecosystems ◽  
Marine Biodiversity ◽  
Microbial Food Webs ◽  
Marine Habitats ◽  
Ecological Roles ◽  
Marine Viruses

Phytomyxea (plasmodiophorids) is an enigmatic group of obligate biotrophic parasites. Most of the known 41 species are associated with terrestrial and freshwater ecosystems. However, the potential of phytomyxean species to influence marine ecosystems either directly by causing diseases of their hosts or indirectly as vectors of viruses is enormous, although still unexplored. In all, 20% of the currently described phytomyxean species are parasites of some of the key primary producers in the ocean, such as seagrasses, brown algae and diatoms; however, information on their distribution, abundance and biodiversity is either incomplete or lacking. Phytomyxean species influence fitness by altering the metabolism and/or the reproductive success of their hosts. The resulting changes can (1) have an impact on the biodiversity within host populations, and (2) influence microbial food webs because of altered availability of nutrients (e.g. changed metabolic status of host, transfer of organic matter). Also, phytomyxean species may affect their host populations indirectly by transmitting viruses. The majority of the currently known single-stranded RNA marine viruses structurally resemble the viruses transmitted by phytomyxean species to crops in agricultural environments. Here, we explore possible ecological roles of these parasites in marine habitats; however, only the inclusion of Phytomyxea in marine biodiversity studies will allow estimation of the true impact of these species on global primary production in the oceans.

scholarly journals A multitrophic model to quantify the effects of marine viruses on microbial food webs and ecosystem processes

2015 ◽  
Vol 9 (6) ◽  
pp. 1352-1364 ◽  
Author(s):  
Joshua S Weitz ◽  
Charles A Stock ◽  
Steven W Wilhelm ◽  
Lydia Bourouiba ◽  
Maureen L Coleman ◽  
...  
Keyword(s):  
Food Webs ◽  
Ecosystem Processes ◽  
Microbial Food Webs ◽  
Marine Viruses

scholarly journals Architecture of Marine Food Webs: to be or not be a ‘small-world’

2018 ◽  
Author(s):  
Tomás Ignacio Marina ◽  
Leonardo A. Saravia ◽  
Georgina Cordone ◽  
Vanesa Salinas ◽  
Santiago R. Doyle ◽  
...  
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Path Length ◽  
Small World ◽  
Marine Ecosystems ◽  
Characteristic Path Length ◽  
Structural Pattern ◽  
Marine Food Webs ◽  
Marine Habitats ◽  
Marine Food

AbstractThe search for general properties in network structure has been a central issue for food web studies in recent years. One such property is the small-world topology that combines a high clustering and a small distance between nodes of the network. This property may increase food web resilience but make them more sensitive to the extinction of connected species. Food web theory has been developed principally from freshwater and terrestrial ecosystems, largely omitting marine habitats. If theory needs to be modified to accommodate observations from marine ecosystems, based on major differences in several topological characteristics is still on debate. Here we investigated if the small-world topology is a common structural pattern in marine food webs. We developed a novel, simple and statistically rigorous method to examine the largest set of complex marine food webs to date. More than half of the analyzed marine networks exhibited a similar or lower characteristic path length than the random expectation, whereas 39% of the webs presented a significantly higher clustering than its random counterpart. Our method proved that 5 out of 28 networks fulfilled both features of the small-world topology: short path length and high clustering. This work represents the first rigorous analysis of the small-world topology and its associated features in high-quality marine networks. We conclude that such topology is a structural pattern that is not maximized in marine food webs; thus it is probably not an effective model to study robustness, stability and feasibility of marine ecosystems.

scholarly journals Elevated temperature and browning increase dietary methylmercury, but decrease essential fatty acids at the base of lake food webs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pianpian Wu ◽  
Martin J. Kainz ◽  
Fernando Valdés ◽  
Siwen Zheng ◽  
Katharina Winter ◽  
...  
Keyword(s):  
Climate Change ◽  
Fatty Acids ◽  
Organic Matter ◽  
Food Webs ◽  
Essential Fatty Acids ◽  
Trophic Levels ◽  
Climate Change Scenarios ◽  
Essential Nutrients ◽  
Aquatic Food Webs ◽  
Aquatic Food

AbstractClimate change scenarios predict increases in temperature and organic matter supply from land to water, which affect trophic transfer of nutrients and contaminants in aquatic food webs. How essential nutrients, such as polyunsaturated fatty acids (PUFA), and potentially toxic contaminants, such as methylmercury (MeHg), at the base of aquatic food webs will be affected under climate change scenarios, remains unclear. The objective of this outdoor mesocosm study was to examine how increased water temperature and terrestrially-derived dissolved organic matter supply (tDOM; i.e., lake browning), and the interaction of both, will influence MeHg and PUFA in organisms at the base of food webs (i.e. seston; the most edible plankton size for zooplankton) in subalpine lake ecosystems. The interaction of higher temperature and tDOM increased the burden of MeHg in seston (< 40 μm) and larger sized plankton (microplankton; 40–200 μm), while the MeHg content per unit biomass remained stable. However, PUFA decreased in seston, but increased in microplankton, consisting mainly of filamentous algae, which are less readily bioavailable to zooplankton. We revealed elevated dietary exposure to MeHg, yet decreased supply of dietary PUFA to aquatic consumers with increasing temperature and tDOM supply. This experimental study provides evidence that the overall food quality at the base of aquatic food webs deteriorates during ongoing climate change scenarios by increasing the supply of toxic MeHg and lowering the dietary access to essential nutrients of consumers at higher trophic levels.

Microbial Food Webs in an Artificially Divided Acidic Bog Lake

1998 ◽  
Vol 83 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Karel Šimek ◽  
Dieter Babenzien ◽  
Thomas Bittl ◽  
Rainer Koschel ◽  
Miroslav Macek ◽  
...  
Keyword(s):  
Food Webs ◽  
Microbial Food Webs

scholarly journals Simple models combining competition, defence and resource availability have broad implications in pelagic microbial food webs

2018 ◽  
Vol 21 (9) ◽  
pp. 1440-1452 ◽  
Author(s):  
Selina Våge ◽  
Gunnar Bratbak ◽  
Jorun Egge ◽  
Mikal Heldal ◽  
Aud Larsen ◽  
...  
Keyword(s):  
Food Webs ◽  
Resource Availability ◽  
Microbial Food Webs ◽  
Simple Models

Marine Metazoan Modern Mass Extinction: Improving Predictions by Integrating Fossil, Modern, and Physiological Data

2019 ◽  
Vol 11 (1) ◽  
pp. 369-390 ◽  
Author(s):  
Piero Calosi ◽  
Hollie M. Putnam ◽  
Richard J. Twitchett ◽  
Fanny Vermandele
Keyword(s):  
Global Change ◽  
Extinction Risk ◽  
Biodiversity Loss ◽  
Marine Ecosystems ◽  
Physiological Data ◽  
Marine Biodiversity ◽  
Global Changes ◽  
History Of ◽  
Extinction Events ◽  
Modern Mass

Evolution, extinction, and dispersion are fundamental processes affecting marine biodiversity. Until recently, studies of extant marine systems focused mainly on evolution and dispersion, with extinction receiving less attention. Past extinction events have, however, helped shape the evolutionary history of marine ecosystems, with ecological and evolutionary legacies still evident in modern seas. Current anthropogenic global changes increase extinction risk and pose a significant threat to marine ecosystems, which are critical for human use and sustenance. The evaluation of these threats and the likely responses of marine ecosystems requires a better understanding of evolutionary processes that affect marine ecosystems under global change. Here, we discuss how knowledge of ( a) changes in biodiversity of ancient marine ecosystems to past extinctions events, ( b) the patterns of sensitivity and biodiversity loss in modern marine taxa, and ( c) the physiological mechanisms underpinning species’ sensitivity to global change can be exploited and integrated to advance our critical thinking in this area.

scholarly journals Species check-list for Tintinnids of the Philippines Archipelago (Protozoa, Ciliophora)

ZooKeys ◽  
2018 ◽  
Vol 771 ◽  
pp. 1-14
Author(s):  
Jane Abigail Santiago ◽  
Maria Carmen Lagman
Keyword(s):  
Food Webs ◽  
Marine Environment ◽  
Coastal Waters ◽  
The Philippines ◽  
Marine Biodiversity ◽  
Check List ◽  
Planktonic Ciliates ◽  
Protozoa Ciliophora

Tintinnids are an essential link between nano- and macro- planktons in the food webs of the marine environment. It is also known that tintinnids are one of themajor components of marine planktonic ciliates and has a cosmopolitan character. In the Philippine archipelago, which is recognized as a center of marine biodiversity, tintinnids checklist has not been done or published. Therefore, a checklist is presented in this study based on a compilation of previous tintinnids studies conducted at the Philippines waters. As a result of the studies done since 1941 up to present, a total of 114 taxa belonging to 14 families and 37 genera were listed. The Philippines coastal waters record a total of 50 species while the open seas document 72 species to date.

scholarly journals Microbial food web dynamics along a soil chronosequence of a glacier forefield

2011 ◽  
Vol 8 (11) ◽  
pp. 3283-3294 ◽  
Author(s):  
J. Esperschütz ◽  
A. Pérez-de-Mora ◽  
K. Schreiner ◽  
G. Welzl ◽  
F. Buegger ◽  
...  
Keyword(s):  
Food Web ◽  
Microbial Communities ◽  
Food Webs ◽  
Litter Decomposition ◽  
Developmental Stages ◽  
Food Web Dynamics ◽  
Glacier Forefield ◽  
Microbial Food Webs ◽  
And Function ◽  
The 19Th Century

Abstract. Microbial food webs are critical for efficient nutrient turnover providing the basis for functional and stable ecosystems. However, the successional development of such microbial food webs and their role in "young" ecosystems is unclear. Due to a continuous glacier retreat since the middle of the 19th century, glacier forefields have expanded offering an excellent opportunity to study food web dynamics in soils at different developmental stages. In the present study, litter degradation and the corresponding C fluxes into microbial communities were investigated along the forefield of the Damma glacier (Switzerland). 13C-enriched litter of the pioneering plant Leucanthemopsis alpina (L.) Heywood was incorporated into the soil at sites that have been free from ice for approximately 10, 60, 100 and more than 700 years. The structure and function of microbial communities were identified by 13C analysis of phospholipid fatty acids (PLFA) and phospholipid ether lipids (PLEL). Results showed increasing microbial diversity and biomass, and enhanced proliferation of bacterial groups as ecosystem development progressed. Initially, litter decomposition proceeded faster at the more developed sites, but at the end of the experiment loss of litter mass was similar at all sites, once the more easily-degradable litter fraction was processed. As a result incorporation of 13C into microbial biomass was more evident during the first weeks of litter decomposition. 13C enrichments of both PLEL and PLFA biomarkers following litter incorporation were observed at all sites, suggesting similar microbial foodwebs at all stages of soil development. Nonetheless, the contribution of bacteria, especially actinomycetes to litter turnover became more pronounced as soil age increased in detriment of archaea, fungi and protozoa, more prominent in recently deglaciated terrain.

Sign in / Sign up

Export Citation Format

Share Document