Molecular diet studies of water mites reveal prey biodiversity

Water mites are diverse aquatic invertebrates that provide potentially important ecosystem and economic services as bioindicators and mosquito biocontrol; however, little is known about water mite digestive physiology, including their diet in nature. Water mites, much like their spider relatives, liquefy their prey upon consumption. This results in the absence of morphologically identifiable prey in water mite mid-gut. Previous studies have reported associations in the field of water mites with presumed prey and laboratory observations of water mites feeding on specific organisms offered for ingestion; however, the present work aims to determine what water mites have ingested in nature based on molecular studies of gut contents from freshly collected organisms from the field. To elucidate water mite prey, we used next-generation sequencing to detect diverse cytochrome oxidase I DNA barcode sequences of putative prey in the guts of 54 specimens comprising two species of Lebertia and a few specimens of Arrenurus (2) and Limnesia (1). To our knowledge this is the first molecular study of the diets of water mites as they feed in nature. While the presence of chironomid DNA confirmed previous observations of midge larvae as part of the diets of Lebertia, we also found the DNA of diverse organisms in all four species of water mites, including the DNA of mosquitoes in 6 specimens of Lebertia and a large number of previously unknown prey, especially from oligochaete worms. These studies thereby reveal a greater diversity of prey and a potentially broader significance than previously appreciated for water mites in aquatic food webs. Molecular studies like this can detect water mite predators of mosquito larvae and add knowledge of water mite predatory contributions to freshwater food webs.

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7. Measuring the Rate of Mercury Loss in Amphipod Gut and Tissues after Exposure to Contaminated Sediments

Inquiry@Queen's Undergraduate Research Conference Proceedings ◽

10.24908/iqurcp.7866 ◽

2017 ◽

Author(s):

Jonathan Martin

Keyword(s):

Food Webs ◽

Yellow Perch ◽

Food Source ◽

Perca Flavescens ◽

Artificial Substrates ◽

Gut Contents ◽

Before And After ◽

Aquatic Food ◽

Health Canada ◽

St Lawrence River

Mercury (Hg) contamination of the St. Lawrence River along the Cornwall waterfront is the result of over a century of industrial inputs. Yellow perch (Perca flavescens) are contaminated above the consumption guidelines deemed safe by Health Canada in one of three contaminated depositional zones. Amphipods are crustaceans that play an important role in aquatic food webs, and a recent study of the diet of yellow perch showed that amphipods were the primary food source of yellow perch in these zones and that amphipods showed similar patterns of Hg contamination. However, not all Hg taken up by amphipods is bioavailable. That is, not all Hg is incorporated into the tissues and available for uptake by yellow perch. To determine if Hg analyses of amphipods are biased by Hg present in their gut contents, the rate of Hg loss was measured from the gut and tissues. Amphipods were collected in the field using artificial substrates. A sample was frozen immediately upon retrieval, and the remaining amphipods were kept in a sieve in a basin of filtered river water. Amphipods were then sampled over 16 days to compare Hg concentrations in gut contents and tissues before and after they were removed from the Hg source in the field. The data were used to estimate the portion of Hg bioavailable to yellow perch. This enables us to more accurately estimate the extent of Hg contamination that is moving through the Cornwall food web, leading to elevated concentrations in top trophic fish species.

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Chironomidae feeding habits in different habitats from a Neotropical floodplain: exploring patterns in aquatic food webs

Brazilian Journal of Biology ◽

10.1590/1519-6984.14614 ◽

2016 ◽

Vol 76 (1) ◽

pp. 117-125 ◽

Cited By ~ 5

Author(s):

C. M. M. Butakka ◽

F. H. Ragonha ◽

S. Train ◽

G. D. Pinha ◽

A. M. Takeda

Keyword(s):

Food Webs ◽

Feeding Habits ◽

Fungal Spores ◽

Gut Contents ◽

Larval Feeding ◽

Gut Content ◽

Aquatic Communities ◽

Food Items ◽

Aquatic Food ◽

Almost All

Abstract Ecological studies on food webs have considerably increased in recent decades, especially in aquatic communities. Because Chironomidae family are highly specious, occurring in almost all aquatic habitats is considered organisms-key to initiate studies on ecological relationships and trophic webs. We tested the hypothesis that the diversity of the morphospecies diet reflects differences on both the food items available among habitats and the preferences of larval feeding. We analyzed the gut content of the seven most abundant Chironomidae morphospecies of the different habitats from the Upper Paraná River. We categorized the food items found into algae, fungal spores, fragments of plants, algae and animal fragments and sponge spicules. We observed the algae predominance in the gut content of morphospecies from lakes. Considering the different regions from each lake, we registered the highest food abundance in the littoral regions in relation to the central regions. From the variety of feeding habits (number of item kinds), we classified Chironomus strenzkei, Tanytarsus sp.1, Procladius sp.1 as generalist morphospecies. We found a nested pattern between food items and Chironomidae morphospecies, where some items were common to all taxa (e.g., Bacillariophyceae algae, especially), while others were found in specific morphospecies (e.g., animals fragments found in Procladius sp.1). The algae represented the most percentage of gut contents of Chironomidae larvae. This was especially true for the individuals from littoral regions, which is probably due to the major densities of algae associated to macrophytes, which are abundant in these regions. Therefore, the feeding behavior of these morphospecies was generalist and not selective, depending only of the available resources.

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A description of two new species of water mites of the genus Torrenticola Piersig, 1896 (Acariformes: Hydrachnidia: Torrenticolidae) from the Krasnodar Kray, Russia

Zoosystematica Rossica ◽

10.31610/zsr/2013.22.2.181 ◽

2013 ◽

Vol 22 (2) ◽

pp. 181-188

Author(s):

P.V. Tuzovskij

Keyword(s):

New Species ◽

Mite Species ◽

Running Waters ◽

Water Mites ◽

North Caucasus ◽

Water Mite ◽

The North ◽

Two New Species

Two new water mite species, Torrenticola amplexella and T. krasnodarensis, from running waters of the North Caucasus (Krasnodar Kray) are described with illustrations.

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Faculty Opinions recommendation of Neonicotinoids disrupt aquatic food webs and decrease fishery yields.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.736836591.793566835 ◽

2019 ◽

Author(s):

Michael Symonds

Keyword(s):

Food Webs ◽

Aquatic Food Webs ◽

Aquatic Food

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

Scientific Reports ◽

10.1038/s41598-021-95742-9 ◽

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.

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Eutrophication induces shifts in the trophic position of invertebrates in aquatic food webs

Ecology ◽

10.1002/ecy.3275 ◽

2020 ◽

Author(s):

Gea H. Lee ◽

J. Arie Vonk ◽

Ralf C.M. Verdonschot ◽

Michiel H.S. Kraak ◽

Piet F.M. Verdonschot ◽

...

Keyword(s):

Food Webs ◽

Trophic Position ◽

Aquatic Food Webs ◽

Aquatic Food

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Assessing the utility of sulfur isotope values for understanding mercury concentrations in water and biota from high Arctic lakes

Arctic Science ◽

10.1139/as-2018-0022 ◽

2019 ◽

Vol 5 (2) ◽

pp. 90-106 ◽

Cited By ~ 1

Author(s):

Gretchen L. Lescord ◽

Meredith G. Clayden ◽

Karen A. Kidd ◽

Jane L. Kirk ◽

Xiaowa Wang ◽

...

Keyword(s):

Food Webs ◽

Total Mercury ◽

Nitrogen Isotopes ◽

Sulfur Isotopes ◽

High Arctic ◽

Arctic Lakes ◽

Carbon And Nitrogen ◽

Resolute Bay ◽

Aquatic Food ◽

Globally Stable

Methylmercury (MeHg) biomagnifies through aquatic food webs resulting in elevated concentrations in fish globally. Stable carbon and nitrogen isotopes are frequently used to determine dietary sources of MeHg and to model its biomagnification. However, given the strong links between MeHg and sulfur cycling, we investigated whether sulfur isotopes (δ34S) would improve our understanding of MeHg concentrations ([MeHg]) in Arctic lacustrine food webs. Delta34S values and total mercury (THg) or MeHg were measured in water, sediments, and biota from six lakes near Resolute Bay, NU, Canada. In two lakes impacted by historical eutrophication, aqueous sulfate δ34S was ∼8‰ more positive than sedimentary δ34S, suggestive of bacterial sulfate reduction in the sediment. In addition, aqueous δ34S showed a significant positive relationship with aqueous [MeHg] across lakes. Within taxa across lakes, [THg] in Arctic char muscle and [MeHg] in their main prey, chironomids, were positively related to their δ34S values across lakes, but inconsistent relationships were found across entire food webs among lakes. Across lakes, nitrogen isotopes were better predictors of biotic [THg] and [MeHg] than δ34S within this dataset. Our results suggest some linkages between Hg and S biogeochemistry in high Arctic lakes, which is an important consideration given anticipated climate-mediated changes in nutrient cycling.

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On the systematics of the water mites Hygrobates nigromaculatus Lebert, 1879 and H. setosus Besseling, 1942 (Acari, Hydrachnidia, Hygrobatidae)

Zootaxa ◽

10.11646/zootaxa.4277.1.2 ◽

2017 ◽

Vol 4277 (1) ◽

pp. 17 ◽

Cited By ~ 2

Author(s):

PETR V. TUZOVSKIJ

Keyword(s):

Comparative Analysis ◽

Water Mites ◽

Water Mite

The first description of the deutonymph of the water mite Hygrobates setosus and a redescription of larvae, females and males of H. nigromaculatus and H. setosus are presented, with a comparative analysis of some morphological structures in all active stages of both species.

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