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opencc-zeroDec 2016View details →

Data from: Testing the validity of functional response models using molecular gut content analysis for prey choice in soil predators

Analysis of predator - prey interactions is a core concept of animal ecology, explaining structure and dynamics of animal food webs. Measuring the functional response, i.e. the intake rate of a consumer as a function of prey density, is a powerful method to predict the strength of trophic links and assess motives of prey choice, particularly in arthropod communities. However, due to their reductionist set-up, functional responses, which are based on laboratory feeding experiments, may not display field conditions, possibly leading to skewed results. Here, we tested the validity of functional responses of centipede predators and their prey by comparing them with empirical gut content data from field-collected predators. Our predator - prey system included lithobiid and geophilomorph centipedes, abundant and widespread predators of forest soils and their soil-dwelling prey. First, we calculated the body size-dependent functional responses of centipedes using a published functional response model in which we included natural prey abundances and animal body masses. This allowed us to calculate relative proportions of specific prey taxa in the centipede diet. In a second step, we screened field-collected centipedes for DNA of eight abundant soil-living prey taxa and estimated their body size-dependent proportion of feeding events. We subsequently compared empirical data for each of the eight prey taxa, on proportional feeding events with functional response-derived data on prey proportions expected in the gut, showing that both approaches significantly correlate in five out of eight predator - prey links for lithobiid centipedes but only in one case for geophilomorph centipedes. Our findings suggest that purely allometric functional response models, which are based on predator-prey body size ratios are too simple to explain predator - prey interactions in a complex system such as soil. We therefore stress that specific prey traits, such as defence mechanisms, must be considered for accurate predictions.

FIGURE 2A–E in A new species of water mite (Acari, Hydrachnidia) from Assam, India, found in the gut contents of the fish Botia dario (Botiidae)

FIGURE 2A–E. Torrenticola episce sp. nov., holotype male: A = dorsal shield; B = ventral shield; C = gnathosoma; D = palp, medial view; E = palp, lateral view. Scale bars = 100 Μm.

FIGURE 4A–C. A–B in A new species of water mite (Acari, Hydrachnidia) from Assam, India, found in the gut contents of the fish Botia dario (Botiidae)

FIGURE 4A–C. A–B Hygrobates cf. sinensis Uchida & Imamura, 1951, female: A = genital field; B = palp. C Torrenticola haliki Pešić & Smit, 2010, male: palp, medial view. Scale bars = 100 Μm.

FIGURE 1A–B. A in A new species of water mite (Acari, Hydrachnidia) from Assam, India, found in the gut contents of the fish Botia dario (Botiidae)

FIGURE 1A–B. A) Sampling site (Kakarikata beel, Majuli Island, Assam State, India; (B) the fish Botia dario (Hamilton, 1822).

FIGURE 3A–C in A new species of water mite (Acari, Hydrachnidia) from Assam, India, found in the gut contents of the fish Botia dario (Botiidae)

FIGURE 3A–C. Torrenticola episce sp. nov., paratype female: A = dorsal shield; B = ventral shield; C = palp, medial view. Scale bars = 100 Μm.

opencc-zeroFeb 2022View details →

Deciphering the diet of a wandering spider (Phoneutria boliviensis; Araneae: Ctenidae) by DNA metabarcoding of gut contents

Arachnids are the most abundant land predators. Despite the importance of their functional roles as predators and the necessity to understand their diet for conservation, the trophic ecology of many arachnid species has not been sufficiently studied. In the case of the wandering spider, Phoneutria boliviensis F. O. Pickard-Cambridge, 1897, only field and laboratory observational studies on their diet exist. By using a DNA metabarcoding approach, we compared the prey found in the gut content of males and females from three distant Colombian populations of P. boliviensis. By DNA metabarcoding of the cytochrome c oxidase subunit I (COI), we detected and identified 234 prey items (individual captured by the spider) belonging to 96 operational taxonomic units (OTUs), as prey for this wandering predator. Our results broaden the known diet of P. boliviensis with at least 75 prey taxa not previously registered in fieldwork or laboratory experimental trials. These results suggest that P. boliviensis feeds predominantly on invertebrates (Diptera, Lepidoptera, Coleoptera and Orthoptera) and opportunistically on small squamates. Intersex and interpopulation differences were also observed. Assuming that prey preference does not vary between populations, these differences are likely associated with a higher local prey availability. Finally, we suggest that DNA metabarcoding can be used for evaluating subtle differences in the diet of distinct populations of P. boliviensis, particularly when predation records in the field cannot be established or quantified using direct observation.

opencc-zeroJun 2022View details →

Molecular gut content analysis indicates the inter- and intra-guild predation patterns of spiders in conventionally managed vegetable fields

Inter- and intra-guild interactions are important in the coexistence of predators and their prey, especially in highly disturbed vegetable cropping systems with sporadic food resources. Assessing the dietary range of a predator taxon characterized by diverse foraging behavior using conventional approaches, such as visual observation and conventional molecular approaches for prey detection, has serious logistical problems. In this study, we investigated the trophic interactions of a functionally diverge group of predators -spiders- to accomplish the ultimate goal that is the predation of spiders on major crop pests. We used high-throughput sequencing (HTS) and biotic interaction networks to precisely annotate the predation spectrum and highlight the predator–predator and predator-prey interactions in Brassica fields. The prey taxa in the gut of spiders were mainly enriched with insects (including dipterans, coleopterans, orthopterans, hemipterans and lepidopterans) and arachnids (such as Araneae) along with a wide range of other prey factions. Despite the generalist foraging behavior of spiders, the community structure analysis and interaction networks highlighted the overrepresentation of particular prey taxa in the gut of each spider family, as well as showed the intra-family predation between different spiders. Identifying the diverse trophic niche proportions underpins the importance of spiders as predators of pests in highly disturbed agroecosystems. More specifically, combining HTS with advanced ecological community analysis reveals the preferences and biological control potential of particular spider taxa, so provides a valuable evidence base for targeted conservation biological control efforts in complex trophic networks.

opencc-by-4.0Jul 2022View details →

Tadnoll Brook gut content dataset

This dataset contains feeding interactions of the organisms in Tadnoll Brook food web.

opennotspecifiedMar 2018View details →

FIGURE 25. Gut contents from Potamyia flavata Banks 1934 larvae. A in The larva and pupa of Potamyia flavata (Banks 1934) (Trichoptera: Hydropsychidae): Description, life cycle, and notes on its biology

FIGURE 25. Gut contents from Potamyia flavata Banks 1934 larvae. A = diatoms, B = green algae, C = detritus, D = filamentous algae, E = insect legs.

opennotspecifiedSep 2021View details →

Fig. 2 in Gut-content analysis in four species, combined with comparative analysis of trophic traits, suggests an araneophagous habit for the entire family Palpimanidae (Araneae)

Fig. 2 Comparison of relative 1 conspeccfics spcders cnsects 1 frequency of conspecifics (can- A B nibalism), heterospecific spiders 0.9 0.9 (araneophagy), and insects in 0.8 0.8 the gut of P . gibbulus A, P . 0.7 0.7 potteri B , Diaphorocellus C and frequency Otiothops D . Proportions are 0.6 0.6 estimated per all individuals in e 0.5 0.5 a class (male, female, juvenile). 0.4 0.4 Frequency of cannibalism can be overestimated (see "Discus- Rela 0.3 0.3 sion" for more details), thus 0.2 0.2 should be interpreted with 0.1 0.1 caution 0 0 male female female juvencle adult juvencle adult

opennotspecifiedSep 2021View details →

Fig. 3 in Gut-content analysis in four species, combined with comparative analysis of trophic traits, suggests an araneophagous habit for the entire family Palpimanidae (Araneae)

Fig. 3 Phylogeny of Palpimanidae plus three other families on the genus level, with estimates of the probabilities of each of five traits at nodes. The fuller the symbol, the higher the probability of a presence of the trait. For trait values at terminals see Table S7

opencc-zeroDec 2012View details →

Data from: A molecular gut content study of Themisto abyssorum (Amphipoda) from Arctic hydrothermal vent and cold seep systems

The use of DNA as a marker for prey inside the gut of predators has been instrumental in further understanding of known and unknown interactions. Molecular approaches are in particular useful in unavailable environments like the deep-sea. Trophic interactions in the deep-sea are difficult to observe in situ, correct deep-sea experimental laboratory conditions are difficult to obtain, animals rarely survive the sampling, or the study organisms feed during the sampling due to long hauls. Preliminary studies of vent and seep systems in the Nordic Seas have identified the temperate-cold water pelagic amphipod Themisto abyssorum as a potentially important predator these chemosynthetic habitats. However, the prey of this deep-sea predator is poorly known, and we applied Denaturing High Performance Liquid Chromatography (DHPLC) to investigate the predator - prey interactions of T. abyssorum in deep-water vent and seep systems. Two deep-water hydrothermally active localities (The Jan Mayen and Loki's Castle vent fields) and one cold seep locality (The Håkon Mosby mud volcano) in the Nordic Seas were sampled, genomic DNA of the stomachs of T. abyssorum was extracted, and 18S rDNA gene was amplified and used to map the stomach content. We found a wide range of organisms including micro-eukaryotes, metazoans and detritus. Themisto abyssorum specimens from Loki's Castle had the highest diversity of prey. The wide range of prey items found suggests that T. abyssorum might be involved in more than one trophic level and should be regarded as an omnivore and not a strict carnivore as have previously been suggested.

opencc-zeroDec 2009View details →

Data from: Molecular analysis of parasitoid linkages (MAPL): gut contents of adult parasitoid wasps reveal larval host

Metamorphosing insects often have complex and poorly known life-histories. In particular, what they feed on during their larval stages remains unknown for the vast majority of species and its documentation only results from difficult and time-intensive field observations, rearing or dissections. Through the application of a DNA analysis of gut contents in adult parasitoid wasps, we were able to selectively sequence a diagnostic DNA marker that permitted the identification of the host used by these wasps during their larval stages. By reproducing these results in species with different life-histories, we excluded other potential sources of host DNA, confirming that after ingestion by the parasitoid larva the host DNA can persist through metamorphosis in the abdominal contents of the adult wasp. Our discovery considerably extends the applicability of molecular analysis of gut contents by enabling documentation of the food used by insects during their larval stages and thus increasing the accuracy and precision of food web-studies. The 24% success rate of our approach is surprisingly high considering the challenging context for host DNA preservation, and we discuss the factors possibly affecting this rate. We propose Molecular Analysis of Parasitoid Linkages (MAPL) as a new method to document host-parasitoid associations at a faster pace and with unrivalled precision. Because of the key regulatory role of parasitoid wasps in ecosystems, which makes them the most commonly used biological control agents, MAPL will have immediate applications in both basic and applied biological sciences.

Figure 3. A in Is the gut content of Milnesium (Eutardigrada) related to buccal tube size?

Figure 3. A, Milnesium sp. feeding on a rotifer and with rotifer remnants in the gut; B, remnants of rotifers in the gut of Milnesium sp.; C, rotifer and tardigrade (Macrobiotus sp.) remnants in the gut of Milnesium sp.; D, tardigrade remnants (Mesobiotus szeptyckii Kaczmarek & Michalczyk, 2009) in the gut of Milnesium beatae. Scale bars in micrometres.

Figure 1 in Is the gut content of Milnesium (Eutardigrada) related to buccal tube size?

Figure 1. The relationship between the buccal tube dimensions (length and standard width) and three types of prey remnants observed in the guts of various Milnesium spp. specimens.

Figure 2 in Is the gut content of Milnesium (Eutardigrada) related to buccal tube size?

Figure 2. Differences in the gut contents of various Milnesium spp. specimens in relation to: A, Milnesium body length; B, buccal tube length; C, buccal tube standard width; and D, buccal tube standard width/length ratio. Horizontal line = median; box = quartiles; whiskers = minimum and maximum within the 1.5 interquartile range; circles and asterisks = outliers.

Figure 4. A in Is the gut content of Milnesium (Eutardigrada) related to buccal tube size?

Figure 4. A, amoeba remnants in the gut of Milnesium bohleberi Bartels et al., 2014; B, Milnesium sp. feeding on a nematode; C, an unidentifiable matrix in the gut of Milnesium sp. Scale bars in micrometres.

opencc-zeroSep 2021View details →

Genotypes for herring samples collected from Chinook salmon gut contents

Dynamic prey resources influence foraging opportunities for consumers. In coastal food webs, forage fish abundance and seasonal reproduction mediate foraging opportunities for mobile consumers. Recent declines in Chinook salmon productivity have prompted efforts to determine whether poormarine survival is caused by limited feeding opportunities. To establish the importance of phenological diversity in Pacific herring for Chinook salmon, we used genetic stock identification to assign individual herring collected from the guts of juvenile and adult Chinook salmon to populations with distinct spawning phenologies. The majority of herring in the guts of adult Chinook salmon across seasons and geographic areas were dominated by the March–April herring spawn group, but juvenile Chinook salmon diets varied seasonally, with a higher proportion of January–February spawners in summer than in spring. Our results suggest that (1) population diversity of Pacific herring is used by juvenile Chinook salmon and thus contributes to their growth, and (2) stock-specific distribution of Pacific herring extends well beyond documented spawning grounds. Herring population diversity may therefore support foraging opportunities for Chinook salmon during a critical period and highlights the need for future research to quantify seasonal distribution and abundance of phenologically distinct groups of Pacific herring within Salish Sea.

opennotspecifiedJun 2023View details →

FIGURE 25. Solasteridae Gut Contents. Solaster regularis USNM 1137298 gut contents. A. Actinal view. B in New Genera, Species, and observations on the biology of Antarctic Valvatida (Asteroidea)

FIGURE 25. Solasteridae Gut Contents. Solaster regularis USNM 1137298 gut contents. A. Actinal view. B. Closeup of Anasterias (identified as GUTcon) in S. regularis gut. C. Closeup of paxillae (identified as GUTcon) in Lophaster stellans USNM 1664405 gut.