scholarly journals What Is the Carcass-Usage Mode of the Collembola? A Case Study of Entomobrya proxima in the Laboratory

Insects ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 67 ◽  
Author(s):  
Lichao Feng ◽  
Liang Chang ◽  
Shaoqing Zhang ◽  
Xinyu Zhu ◽  
Sina Adl ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Food Preference ◽  
Feeding Habits ◽  
Food Resource ◽  
Food Preferences ◽  
Trophic Levels ◽  
Food Sources ◽  
Body Parts ◽  
Animal Food ◽  
Rhizopus Sp

Collembola display a variety of feeding habits, and prey on many types of food at different trophic levels in the soil. In most cases, their feeding selections are widely varied. In the interest of the food preferences of E. proxima, we attempted to confirm how the Collembola utilize food when feeding on carrion (unusual sources). Four different soil animals (with different stable isotope values and increasing trophic levels) were used to examine whether collembolans can use dead insects as a food resource in specific manners, depending on food preference. Our results demonstrated that the food preference of a collembolan changed significantly after feeding on insects with different feeding habits for 60 days. We found that stable isotope values (δ13C) of Entomobrya proxima approached those of the food sources. A large proportion of the diet (more than 50%) should directly consist of insect body parts, with the remainder consisting of indirectly used, mixed microorganisms naturally growing on animal food, such as fungi (Rhizopus sp., Alternaria sp., Penicillium sp., and Aspergillus sp.) and bacteria (Bacillus sp1. and Bacillus sp2.). Based on this research, the food preference of collembolans is more focused on carcasses (dead insect bodies) than microorganisms during the animal-food decomposition process.

scholarly journals Figuring the pecking order

2018 ◽  
Vol 52 (12) ◽  
pp. 2334-2355
Author(s):  
Shona M. Bettany ◽  
Ben Kerrane
Keyword(s):  
Food Preference ◽  
Food Preferences ◽  
Food Product ◽  
Food Products ◽  
Policy Makers ◽  
Animal Food ◽  
Interpretive Study ◽  
Full Compliance ◽  
The Family ◽  
Animal Food Products

PurposeUsing the family activity of hobby stock-keeping (“petstock”) as a context, this paper aims to extend singularization theory to model the negotiations, agencies and resistances of children, parents and petstock, as they work through how animals become food within the boundaries of the family home. In doing so, the authors present an articulation of this process, deciphering the cultural biographies of petstock and leading to an understanding of the emergent array of child animal food-product preferences.Design/methodology/approachData were collected from petstock-keeping parents through a mixture of ethnographic, in-depth interviewing and netnographic engagements in this qualitative, interpretive study; with parents offering experiential insights into animal meat and food-product socialization behaviours played out within the family environments.FindingsThe findings discuss the range of parental behaviours, motivations and activities vis-à-vis petstock, and their children’s responses, ranging from transgression to full compliance, in terms of eating home-raised animal food-products. The discussion illustrates that in the context of petstock, a precocious child food preference agency towards animal meat and food products is reported to emerge.Research limitations/implicationsThis research has empirical and theoretical implications for the understanding of the development of child food preference agency vis-à-vis animal food products in the context of family petstock keeping.Practical implicationsThe research has the potential to inform policy makers around child education and food in regard to how child food preferences emerge and can inform marketers developing food-based communications aimed at children and parents.Originality/valueTwo original contributions are presented: an analysis of the under-researched area of how children’s food preferences towards eating animal food products develop, taking a positive child food-choice agency perspective, and a novel extension of singularization theory, theorizing the radical transformation, from animal to food, encountered by children in the petstock context.

Feeding and grazing in Lake George, Uganda

1973 ◽  
Vol 184 (1076) ◽  
pp. 299-319 ◽  
Keyword(s):  
Food Preference ◽  
Food Selection ◽  
Trophic Levels ◽  
Food Sources ◽  
Cyclopoid Copepod ◽  
Blue Green Algae ◽  
Tilapia Nilotica ◽  
Daily Ingestion ◽  
Herbivorous Species ◽  
Lake George

The fauna of Lake George is dominated by herbivores, in particular the fish Tilapia nilotica and Haplochromis nigripinnis , and the cyclopoid copepod Thermocyclops hyalinus . Digestion, and the assimilation of carbon from algae, by these herbivores were studied in detail. It was found that, contrary to previous observations reported in the literature, both fish and zooplankton were able to digest and assimilate blue-green algae. The diurnal feeding patterns of the herbivores were examined, and methods devised for assessing, in terms of carbon, the daily ingestion of algae. Hence, using biomass data, the total amount grazed by the herbivores was calculated. Estimates of carbon requirements at other trophic levels were made, as was an assessment of the required level of net production by the algae for comparison with figures for standing crop and net algal production measured by other means. Food selection by secondary and tertiary producers is discussed, and in several species age correlated changes in selectivity were examined. Both the major herbivorous species of fish adopt phytoplankton feeding after a period of carnivorous or omnivorous feeding as fry. Thermocyclops hyalinus is herbivorous all its life, but the size of particle taken changes with age. There are more species of carnivorous than herbivorous fish and these exploit a wider variety of food sources; the few species studied also show changes in food preference with age.

scholarly journals Phytoplankton Fuel Fish Food Webs in a Low-Turbidity Temperate Coastal Embayment: A Stable Isotope Approach

2021 ◽  
Vol 8 ◽  
Author(s):  
Goutam Kumar Kundu ◽  
Changseong Kim ◽  
Dongyoung Kim ◽  
Riaz Bibi ◽  
Heeyong Kim ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Food Webs ◽  
Trophic Levels ◽  
Food Sources ◽  
Estuarine Fish ◽  
Multiple Sources ◽  
Terrestrial Organic Matter ◽  
Fish Food ◽  
High Productivity

Trophic contributions of diverse OM sources to estuarine and coastal food webs differ substantially across systems around the world, particularly for nekton (fish, cephalopods, and crustaceans), which utilize basal resources from multiple sources over space and time because of their mobility and feeding behaviors at multiple trophic levels. We investigated the contributions of putative OM sources to fish food webs and assessed the spatiotemporal patterns, structures, and trophic connectivity in fish food webs across four seasons from three closely spaced (10–15 km) sites: an estuarine channel (EC), a deep bay (DB), and an offshore (OS) region in Gwangyang Bay, a high-productivity, low-turbidity estuarine embayment off the Republic of Korea. While nearly all previous studies have focused on few representative species, we examined δ13C and δ15N values of whole nekton communities along with dominant benthic macro-invertebrates, zooplankton, and their putative primary food sources. The δ13C and δ15N values coupled with MixSIAR, a Bayesian mixing model, revealed that these communities utilized multiple primary producers, but phytoplankton comprised the primary trophic contributor (46.6–69.1%). Microphytobenthos (15.8–20.4%) and the seagrass Zostera marina (8.6–19.8%) made substantial contributions, but the role of river-borne terrestrial organic matter was negligible. Spatially different species composition and stable isotope values, but higher utilization of coastal phytoplankton by estuarine fish, indicated disparate food webs structures between the EC and DB/OS coastal areas, with considerable trophic connectivity. Greater overlaps in fish and cephalopod isotopic niches than among other consumers and a higher estimated carbon trophic enrichment factor for EC nekton confirmed feeding migration-mediated biological transport of coastal OM sources to the estuary. Further, the seasonally consistent structures and resource utilization patterns indicate that fish food webs are resilient to changes at lower trophic levels. Our results contrast with those for other highly turbid coastal systems depending highly on diversified basal sources, including exported terrestrial and wetland detritus alongside autochthonous phytoplankton. Finally, this study provides a novel perspective on the role of OM sources in such low turbidity and highly productive coastal embayments and enhances our understanding of marine ecosystems.

The diet of amphioxus in subtropical Hong Kong as indicated by fatty acid and stable isotopic analyses

2008 ◽  
Vol 88 (7) ◽  
pp. 1487-1491 ◽  
Author(s):  
Y. Chen ◽  
S.G. Cheung ◽  
P.K.S. Shin
Keyword(s):  
Hong Kong ◽  
Fatty Acid ◽  
Stable Isotope ◽  
Trophic Levels ◽  
Food Sources ◽  
Filter Feeder ◽  
Total Particulate Matter ◽  
Isotopic Analyses ◽  
Wide Range ◽  
Hong Kong Waters

Fatty acid profiles and carbon (δ13C) and nitrogen (δ15N) stable isotope markers were used to identify the diet of amphioxus in subtropical Hong Kong waters, and to evaluate the role of co-occurring Branchiostoma belcheri and B. malayanum in trophic transfer, in coastal ecosystems. The present results showed that while amphioxus is generally regarded as a filter feeder, total particulate matter in the water column might not be the main food supply. The diet of amphioxus could be traced to comprise a wide range of food sources, from microbes and microplankton to microalgae, based on the stable isotope analysis. Results of fatty acid profile analysis also revealed contributions from dinoflagellates, zooplankton, detritus and bacteria, and minor contribution from diatoms and fungi in the diet of amphioxus in Hong Kong waters. The use of fatty acid and stable isotope analyses further proved that amphioxus can, not only capture and partition such a different size-range of food particles during their feeding, but also assimilate most of them into their body tissue. The present findings suggested that amphioxus may play an important role in marine food webs by transferring microbial production to higher trophic levels through utilizing microbes in seawater as food.

scholarly journals Trophic interactions of meso- and macrozooplankton and fish in the Iceland Sea as evaluated by fatty acid and stable isotope analysis

2012 ◽  
Vol 69 (7) ◽  
pp. 1277-1288 ◽  
Author(s):  
Hildur Petursdottir ◽  
Stig Falk-Petersen ◽  
Astthor Gislason
Keyword(s):  
Fatty Acid ◽  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Trophic Interactions ◽  
Trophic Ecology ◽  
Feeding Habits ◽  
Isotope Analysis ◽  
Trophic Levels ◽  
Amphipod Species ◽  
Blue Whiting

Abstract Petursdottir, H., Falk-Petersen, S., and Gislason, A. 2012. Trophic interactions of meso- and macrozooplankton and fish in the Iceland Sea as evaluated by fatty acid and stable isotope analysis. – ICES Journal of Marine Science, 69: . A trophic study was carried out in August of 2007 and 2008 on the pelagic ecosystem in the Subarctic Iceland Sea. Carbon and nitrogen stable isotopes and fatty acid biomarkers were used to study trophic linkages and the trophic ecology of the most important pelagic species in this ecosystem, with emphasis on capelin (Mallotus villosus). According to 15N enrichment results, there are 3–4 trophic levels in this ecosystem excluding organisms of the microbial loop and birds and mammals. The primarily herbivorous copepod Calanus hyperboreus occupies the lowest trophic level of the animal species studied, and adult capelin and blue whiting (Micromesistius poutassou) occupy the highest level. Calanus spp. proved to be an important dietary component of most of the species studied, the euphausiid species Thysanoessa inermis and T. longicaudata being exceptions. The chaetognath Eukrohnia hamata is a pure carnivore, feeding heavily on Calanus spp., whereas most of the other zooplankton species studied practice an omnivorous–carnivorous feeding mode. The amphipod species Themisto libellula is important in the diet of adult capelin. Adult capelin and blue whiting share the same feeding habits and could therefore be competing for food.

Flexible diet and trophic position of dreissenid mussels as inferred from stable isotopes of carbon and nitrogen

2005 ◽  
Vol 62 (5) ◽  
pp. 1119-1129 ◽  
Author(s):  
David W Garton ◽  
Christopher D Payne ◽  
Joseph P Montoya
Keyword(s):  
Stable Isotope ◽  
Dreissena Polymorpha ◽  
Lake Erie ◽  
Trophic Position ◽  
Nitrogen Isotope ◽  
Isotope Ratios ◽  
Trophic Levels ◽  
Food Sources ◽  
Stable Isotope Ratios ◽  
Western Lake

In this study, the trophic position and food-web impacts of invading zebra mussels (Dreissena polymorpha) were investigated by sampling mussels, seston (= phytoplankton), macrophytes, zooplankton, and surficial sediment in two small inland lakes (1999–2002) and similarly in western Lake Erie (1999 only). Tissues from quagga mussels (Dreissena bugensis) from Lake Erie were also analyzed. Stable-isotope ratios (15N/14N and 13C/12C) were used to identify likely food sources and estimate relative trophic position. For Lake Erie, stable-isotope ratios indicated no diet differences between the two mussel species. For all lakes, zooplankton δ13C was indicative of phytoplanktivory. The 13C stable isotope ratios indicated that seston comprised ~50% of food sources for mussels in Lake Erie, but 73%–97% and 52%–100% of the diet of mussel populations in Lake Wawasee and Clark Lake, respectively. Stable nitrogen isotope ratios placed zooplankton at trophic levels equal to or higher than those of mussels in seven of eight comparisons. Dreissena polymorpha and D. bugensis are able to exploit suspended detritus as a significant energy source, as well as compete directly with zooplankton for seston as a food source and with each other in areas of sympatry.

scholarly journals Dual stable isotope abundances unravel trophic position of estuarine nematodes

2005 ◽  
Vol 85 (6) ◽  
pp. 1401-1407 ◽  
Author(s):  
Tom Moens ◽  
Steven Bouillon ◽  
Fabiane Gallucci
Keyword(s):  
Empirical Evidence ◽  
Trophic Level ◽  
Trophic Position ◽  
Feeding Habits ◽  
Nematode Species ◽  
Trophic Levels ◽  
Food Sources ◽  
Feeding Mode ◽  
Nematode Communities ◽  
Carbon And Nitrogen

The role and quantitative importance of free-living nematodes in marine and estuarine soft sediments remain enigmatic for lack of empirical evidence on the feeding habits and trophic position of most nematode species. Here we use natural abundances of carbon and nitrogen stable isotopes of some abundant nematode species/genera from estuarine intertidal sediments to assess their trophic level and major food sources. In all stations, δ15N of different dominant nematode species/genera spanned a range of 3.6 to 6.3 ppt, indicating that at least two trophic levels were represented. The large nematodes Enoplus brevis, Enoploides longispiculosus and Adoncholaimus fuscus consistently had high δ15N, in line with mouth-morphology based predictions and empirical evidence on their predacious feeding modes. Daptonema sp., Metachromadora remanei, Praeacanthonchus punctatus and ‘Chromadoridae’ (dominated by Ptycholaimellus ponticus) had comparatively lower δ15N, and δ13C suggesting that microphytobenthos (MPB) is their major carbon source, although freshly sedimented particulate organic matter may also contribute to their nutrition in silty sediments. The trophic position of Sphaerolaimus sp., a genus with documented predacious feeding mode, was ambiguous. Ascolaimus elongatus had δ15N signatures indicating a predacious ecology, which is at variance with expectations from existing feeding type classifications. Our study shows that—despite limitations imposed by the biomass requirements for EA-IRMS (elemental analyser—isotope ratio mass spectrometry)—natural isotope abundances of carbon and nitrogen are powerful tools to unravel trophic structure within nematode communities. At the same time, the prominence of different trophic levels results in a large span of δ15N, largely invalidating the use of nitrogen isotope abundances to assess food sources and trophic level of whole nematode communities.

scholarly journals Variability in copepod trophic levels and feeding selectivity based on stable isotope analysis in Gwangyang Bay of the southern coast of the Korean Peninsula

2018 ◽  
Vol 15 (7) ◽  
pp. 2055-2073 ◽  
Author(s):  
Mianrun Chen ◽  
Dongyoung Kim ◽  
Hongbin Liu ◽  
Chang-Keun Kang
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Salinity Gradient ◽  
Isotope Analysis ◽  
Trophic Levels ◽  
Food Sources ◽  
Primary Producers ◽  
Model Calculations ◽  
Δ13c And Δ15n ◽  
Gwangyang Bay

Abstract. Trophic preference (i.e., food resources and trophic levels) of different copepod groups was assessed along a salinity gradient in the temperate estuarine Gwangyang Bay of Korea, based on seasonal investigation of taxonomic results in 2015 and stable isotope analysis incorporating multiple linear regression models. The δ13C and δ15N values of copepods in the bay displayed significant spatial heterogeneity as well as seasonal variations, which were indicated by their significant relationships with salinity and temperature, respectively. Both spatial and temporal variations reflected those in isotopic values of food sources. The major calanoid groups (marine calanoids and brackish water calanoids) had a mean trophic level of 2.2 relative to nanoplankton as the basal food source, similar to the bulk copepod assemblage; however, they had dissimilar food sources based on the different δ13C values. Calanoid isotopic values indicated a mixture of different genera including species with high δ15N values (e.g., Labidocera, Sinocalanus, and Tortanus), moderate values (Calanus sinicus, Centropages, Paracalanus, and Acartia), and relatively low δ15N values (Eurytemora pacifica and Pseudodiaptomus). Feeding preferences of different copepods probably explain these seasonal and spatial patterns of the community trophic niche. Bayesian mixing model calculations based on source materials of two size fractions of particulate organic matter (nanoplankton at < 20 µm vs. microplankton at 20–200 µm) indicated that Acartia and Centropages preferred large particles; Paracalanus, Calanus, Eurytemora, and Pseudodiaptomus apparently preferred small particles. Tortanus was typically carnivorous with low selectivity on different copepods. Labidocera preferred marine calanoids Acartia, Centropages, and harpacticoids; on the other hand, Sinocalanus and Corycaeus preferred brackish calanoids Paracalanus and Pseudodiaptomus. Overall, our results depict a simple energy flow of the planktonic food web of Gwangyang Bay: from primary producers (nanoplankton) and a mixture of primary producers and herbivores (microplankton) through omnivores (Acartia, Calanus, Centropages, and Paracalanus) and detritivores (Pseudodiaptomus, Eurytemora, and harpacticoids) to carnivores (Corycaeus, Tortanus, Labidocera, and Sinocalanus).

scholarly journals Comparison of feeding habits and habitat use between invasive raccoons and native raccoon dogs in Hokkaido, Japan

BMC Ecology ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Aya Osaki ◽  
Mariko Sashika ◽  
Go Abe ◽  
Kohei Shinjo ◽  
Ayako Fujimoto ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Habitat Use ◽  
Native Species ◽  
Agricultural Land ◽  
Feeding Habits ◽  
Food Preferences ◽  
Crop Damage ◽  
Raccoon Dog ◽  
Fecal Analysis ◽  
Raccoon Dogs

Abstract Background In Japan, invasive raccoons cause severe ecological and social problems by transmitting pathogens to humans, livestock, and native species, causing substantial crop damage, and competing with native species. Possible competition between invasive raccoons and native raccoon dogs is of concern in Japan because Japanese raccoon dogs have a limited distribution and are native only to Japan and the two species have similar characteristics. We assessed potential competition between raccoons and raccoon dogs by comparing feeding habits and habitat use. Results Both species were captured in Hokkaido, Japan from 2004 to 2017. More raccoons were captured close to agricultural land at the forest periphery (70.1%, 358/511); conversely, more raccoon dogs were captured in the forest core (74.9%, 253/338). Feeding habits were then examined by fecal analysis and stable isotope analyses. Fecal analysis revealed both species to be opportunistic omnivores that consumed easily found food items. However, raccoon feces contained more crops, whereas raccoon dog feces contained more insects, reflecting the different locations in which the species were trapped. Moreover, stable isotope ratios were significantly higher in raccoons than raccoon dogs (Corn has the highest carbon stable isotope (δ13C) value, and amphibians and reptiles are high in nitrogen stable isotope (δ15N); forest resources such as insects and wild fruits are low in δ13C and δ15N). Conclusions We conclude that both species ate similar food types, but their food preferences appeared to differ. Raccoon and raccoon dog habitat use also differed, possibly because the two species inhabited areas where they could easily obtain their preferred foods. Therefore, the current feeding habits and habitat use of raccoons do not appear to overlap sufficiently with those of raccoon dogs to impact the latter. The results of this study, particularly the stable isotope data, may provide a useful precedent for future studies of competition in medium-sized mammals, particularly canids.

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