scholarly journals Effects of consumer surface sterilization on diet DNA metabarcoding data of terrestrial invertebrates in natural environments and feeding trials

2021 ◽  
Author(s):  
Ana Miller‐ter Kuile ◽  
Austen Apigo ◽  
Hillary S. Young
Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 998
Author(s):  
Tamara Lazic ◽  
Cataldo Pierri ◽  
Giuseppe Corriero ◽  
Bachir Balech ◽  
Frine Cardone ◽  
...  

Seahorses are considered a flagship species for conservation efforts and due to their conservation status, improving knowledge on their dietary composition while applying a non-invasive approach, could be useful. Using Hippocampus guttulatus as a case study, the present study represents pioneering research into investigating the diet of seahorses by NGS-based DNA metabarcoding of fecal samples. The study developed and tested the protocol for fecal DNA metabarcoding during the feeding trials where captive seahorses were fed on a diet of known composition; the process was subsequently applied on fecal samples collected from wild individuals. The analysis of samples collected during the feeding trials indicated the reliability of the applied molecular approach by allowing the characterization of the effectively ingested prey. In the field study, among detected prey species, results revealed that the majority of the seahorse samples contained taxa such as Amphipoda, Decapoda, Isopoda, and Calanoida, while less common prey taxa were Gastropoda and Polyplacophora. As only a small amount of starting fecal material is needed and the sampling procedure is neither invasive nor lethal. The present study indicates DNA metabarcoding as useful for investigating seahorse diet and could help define management and conservation actions.


2018 ◽  
Vol 96 (2) ◽  
pp. 117-125 ◽  
Author(s):  
E. Champagne ◽  
L. Perroud ◽  
A. Dumont ◽  
J.-P. Tremblay ◽  
S.D. Côté

The presence of neighbouring plants and predation risk can affect trophic interactions between plants and herbivores. We hypothesized that the relative preference for neighbouring species would determine winter herbivory and that predation risk would modulate browsing pressure. We tested these hypotheses using feeding trials in two regions with high white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) densities: Outaouais and Anticosti Island (Quebec, Canada). In each, we selected a species of interest and compared browsing rates and time spent foraging with neighbours relatively preferred or avoided. In a subexperiment, we included coyote (Canis latrans Say, 1823) urine to test for threat-sensitive foraging and interactions with neighbour effects. In Outaouais, time spent foraging on the focal species was reduced by the presence of potentially avoided neighbours and deer reduced browsing with increased perceived predation risk. On Anticosti, browsing rates on the focal species increased with avoided neighbours, with no effect of the predator urine. Anticosti deer have been in a predator-free environment for more than 120 years, likely reducing antipredator behaviours. This study demonstrates both neighbour effects and threat-sensitive foraging, phenomena that could interact and thus would benefit from being studied together to better represent trophic interactions in natural environments.


2020 ◽  
Vol 71 (4) ◽  
pp. 512
Author(s):  
Gavin N. Rees ◽  
Michael E. Shackleton ◽  
Garth O. Watson ◽  
Georgia K. Dwyer ◽  
Rick J. Stoffels

A problem for fisheries ecologists who carry out dietary analysis on their specimens is dealing with contents that are difficult to identify, particularly when the contents comprise digested prey. We used a DNA metabarcoding approach to determine the diets of two co-occurring black fish species (Gadopsis bispinosus and Gadopsis marmoratus) to circumvent any issues with trying to apply microscopic methods to identify diets. We examined the frequency of occurrence of taxa across all specimens and the proportion that taxa contributed to total diet. In this way we hoped to demonstrate that a DNA-based method could resolve dietary differences of coexisting taxa. We showed that 10 macroinvertebrate taxa dominated the diets of both species and, of these, 7 occurred in all specimens of both taxa, indicating they were an important component of the diet of both species. Twelve taxa were present only in the G. bispinosus diet and four of those were terrestrial invertebrates; six taxa were found only in G. marmoratus. Our DNA-based approach to examine the taxa in the guts of two co-existing Gadopsis species provided sufficient resolution to show a significant degree of dietary partitioning.


Author(s):  
L. P. Hardie ◽  
D. L. Balkwill ◽  
S. E. Stevens

Agmenellum quadruplicatum is a unicellular, non-nitrogen-fixing, marine cyanobacterium (blue-green alga). The ultrastructure of this organism, when grown in the laboratory with all necessary nutrients, has been characterized thoroughly. In contrast, little is known of its ultrastructure in the specific nutrient-limiting conditions typical of its natural habitat. Iron is one of the nutrients likely to limit this organism in such natural environments. It is also of great importance metabolically, being required for both photosynthesis and assimilation of nitrate. The purpose of this study was to assess the effects (if any) of iron limitation on the ultrastructure of A. quadruplicatum. It was part of a broader endeavor to elucidate the ultrastructure of cyanobacteria in natural systemsActively growing cells were placed in a growth medium containing 1% of its usual iron. The cultures were then sampled periodically for 10 days and prepared for thin sectioning TEM to assess the effects of iron limitation.


2013 ◽  
Vol 18 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Emmanuel Kuntsche ◽  
Florian Labhart

Ecological Momentary Assessment (EMA) is a way of collecting data in people’s natural environments in real time and has become very popular in social and health sciences. The emergence of personal digital assistants has led to more complex and sophisticated EMA protocols but has also highlighted some important drawbacks. Modern cell phones combine the functionalities of advanced communication systems with those of a handheld computer and offer various additional features to capture and record sound, pictures, locations, and movements. Moreover, most people own a cell phone, are familiar with the different functions, and always carry it with them. This paper describes ways in which cell phones have been used for data collection purposes in the field of social sciences. This includes automated data capture techniques, for example, geolocation for the study of mobility patterns and the use of external sensors for remote health-monitoring research. The paper also describes cell phones as efficient and user-friendly tools for prompt manual data collection, that is, by asking participants to produce or to provide data. This can either be done by means of dedicated applications or by simply using the web browser. We conclude that cell phones offer a variety of advantages and have a great deal of potential for innovative research designs, suggesting they will be among the standard data collection devices for EMA in the coming years.


2008 ◽  
Vol 37 (3) ◽  
Author(s):  
Jacek Urbański ◽  
Agata Ślimak

Assessing flood risk and detecting changes of salt water inflow in a coastal micro-tidal brackish marsh using GISIn order to assess changes in salt water inflow and potential flood risks due to sea level rise in a micro-tidal Beka brackish marsh on the Polish Baltic Coast GIS was used. Such wetlands are important elements of coastal zone natural environments. Creating a geodatabase within a GIS system makes it possible to carry out broad analyses of complex systems, such as coastal wetlands. The results indicate that a 40 cm sea-level rise would considerably increase the frequency of flooding in the investigated area, in part because of the small range of the annual sea level oscillations there. A map of the index of changes in saltwater inflow, created with the help of cost-weighted distance (functions), shows that changes which have occurred along the shore, consisting of filling in the drainage channel outlets, have likely had a significant impact on the vegetation of the area.


2020 ◽  
Vol 29 (5) ◽  
pp. 519-535
Author(s):  
Levi Tenen

Aesthetic and historical values are commonly distinguished from each other. Yet there has not been sustained discussion of what, precisely, differs between them. In fact, recent scholarship has focused on various ways in which the two are related. I argue, though, that historical value can differ in an interesting way from aesthetic value and that this difference may have significant implications for environmental preservation. In valuing something for its historical significance, it need not always be the case that there is a reason to want people to experience the entity. Valuing something for its aesthetic merit, by contrast, does imply a reason to want people to experience the entity. I suggest that in virtue of this difference, some historical values may offer better justification for preserving natural environments than do aesthetic considerations.


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