scholarly journals Plankton food for benthic fish: de visu evidence of trophic interaction between rainbow wrasse (Coris julis) and pelagic tunicates (Pegea confoederata)

2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Domenico D'Alelio ◽  
Gabriella Luongo ◽  
Iole Di Capua
Keyword(s):  
Trophic Interactions ◽  
Direct Evidence ◽  
Stomach Contents ◽  
Trophic Interaction ◽  
Benthic Fish ◽  
Marine Animals ◽  
Gulf Of Naples ◽  
Santa Croce ◽  
Rocky Outcrop ◽  
Recreational Scuba

Salps (pelagic tunicates) are rarely observed in nature and trophic interactions involving them mainly rely on the inspection of stomach contents of their potential predators. Moreover, salps have soft bodies that are hardly identified in potential consumers. We involved recreational SCUBA-divers and photographers in collecting de visu evidence of i) massive occurrence of salps and ii) trophic interactions involving salps as preys and benthic animals as consumers. Direct evidence of trophic interactions between salps and benthic fish was documented by photographic frames. We detected a long colony of the salp Pegea confaederata being transported by currents close to the substrate on top of Banco di Santa Croce, an underwater rocky outcrop in the Gulf of Naples (Italy). An individual of the rainbow wrasse Coris julis attacked the above-mentioned salp colony by selectively detaching individuals and biting their stomach. Our report of a trophic interaction between labrids and salps is the second in fifty years and the previous one was only indirect. In this study, citizen science allowed detecting both neglected marine animals like salps and trophic interactions involving them. Visual, direct evidence of predation on salps by benthic fish adds further knowledge about patterns of living-matter fluxes between plankton and benthos, opening new questions on the potential of global change in modifying the efficient circulation of organic matter in marine systems.

scholarly journals Ecological Importance of Cross-Feeding of the Intermediate Metabolite 1,2-Propanediol between Bacterial Gut Symbionts

2020 ◽  
Vol 86 (11) ◽  
Author(s):  
Christopher C. Cheng ◽  
Rebbeca M. Duar ◽  
Xiaoxi Lin ◽  
Maria Elisa Perez-Munoz ◽  
Stephanie Tollenaar ◽  
...  
Keyword(s):  
Trophic Interactions ◽  
Lactobacillus Reuteri ◽  
Trophic Interaction ◽  
Bacterial Strains ◽  
Content Type ◽  
Bifidobacterium Breve ◽  
Gut Symbionts ◽  
Gnotobiotic Mice ◽  
Ecological Importance ◽  
Isogenic Mutants

ABSTRACT Cross-feeding based on the metabolite 1,2-propanediol has been proposed to have an important role in the establishment of trophic interactions among gut symbionts, but its ecological importance has not been empirically established. Here, we show that in vitro growth of Lactobacillus reuteri (syn. Limosilactobacillus reuteri) ATCC PTA 6475 is enhanced through 1,2-propanediol produced by Bifidobacterium breve UCC2003 and Escherichia coli MG1655 from the metabolization of fucose and rhamnose, respectively. Work with isogenic mutants showed that the trophic interaction is dependent on the pduCDE operon in L. reuteri, which encodes the ability to use 1,2-propanediol, and the l-fucose permease (fucP) gene in B. breve, which is required for 1,2-propanediol formation from fucose. Experiments in gnotobiotic mice revealed that, although the pduCDE operon bestows a fitness burden on L. reuteri ATCC PTA 6475 in the mouse digestive tract, the ecological performance of the strain was enhanced in the presence of B. breve UCC2003 and the mucus-degrading species Bifidobacterium bifidum. The use of the respective pduCDE and fucP mutants of L. reuteri and B. breve in the mouse experiments indicated that the trophic interaction was specifically based on 1,2-propanediol. Overall, our work established the ecological importance of cross-feeding relationships based on 1,2-propanediol for the fitness of a bacterial symbiont in the vertebrate gut. IMPORTANCE Through experiments in gnotobiotic mice that employed isogenic mutants of bacterial strains that produce (Bifidobacterium breve) and utilize (Lactobacillus reuteri) 1,2-propanediol, this study provides mechanistic insight into the ecological ramifications of a trophic interaction between gut symbionts. The findings improve our understanding on how cross-feeding influences the competitive fitness of L. reuteri in the vertebrate gut and revealed a putative selective force that shaped the evolution of the species. The findings are relevant since they provide a basis to design rational microbial-based strategies to modulate gut ecosystems, which could employ mixtures of bacterial strains that establish trophic interactions or a personalized approach based on the ability of a resident microbiota to provide resources for the incoming microbe.

scholarly journals Investigating Possible Gastroliths in a Referred Specimen of Bohaiornis guoi (Aves: Enantiornithes)

2021 ◽  
Vol 9 ◽  
Author(s):  
Shumin Liu ◽  
Zhiheng Li ◽  
Alida M. Bailleul ◽  
Min Wang ◽  
Jingmai O’Connor
Keyword(s):  
Digestive System ◽  
Multidisciplinary Approach ◽  
Direct Evidence ◽  
Soft Tissues ◽  
Indirect Evidence ◽  
Stomach Contents ◽  
Gastric Mill ◽  
Limited Evidence ◽  
X Ray ◽  
Two Samples

Gastroliths, where preserved, can provide indirect evidence regarding diet in extinct avian and non-avian dinosaurs. Masses of gastroliths consistent with the presence of a gastric mill are preserved in many Early Cretaceous Jehol birds mostly belonging to the Ornithuromorpha. Gastroliths are also present in basal birds Sapeornis and Jeholornis in which herbivory is supported by direct evidence these taxa consumed seeds in the form of crop or stomach contents. Although gastroliths have been correlated with herbivory in non-avian dinosaurs, the presence of gastroliths and bone together in Ambopteryx calls this association in to question. Despite being known from greater numbers of specimens than other avian lineages, no unequivocal direct or indirect evidence of diet has been recovered from Jehol deposits for the Enantiornithes. A referred specimen of Bohaiornis guoi IVPP V17963 was described as preserving a small number of gastroliths interpreted as rangle, gastroliths whose function is cleaning the stomach in extant raptorial birds. However, based on comparison with gastroliths in other Jehol birds, it has alternatively been suggested that the identified structures are not ingested stones at all but some unusual mineral precipitate. Considering the limited evidence regarding diet in Enantiornithes and the importance of accurately identifying the traces in Bohaiornis in order to understand the enantiornithine digestive system, we extracted two samples of these purported gastroliths and explored these traces using computerized laminography scanning, scanning electron microscopy, energy dispersive x-ray spectroscopy, ground sections, and body size to gastral mass regressions. Similar analyses were conducted on gastroliths extracted from undisputed gastral masses of two Jehol ornithuromorphs and the non-avian pennaraptoran Caudipteryx. The combined results contradict the hypothesis that these traces are gastroliths and supports the interpretation they are mineral precipitate, most likely authigenic quartz (chalcedony). Although authigenesis is commonly responsible for the preservation of soft tissues, it is unclear if these traces record part of the tissues of this Bohaiornis. This study highlights the importance of a multidisciplinary approach in understanding unusual traces in the fossil record and reveal a previously unidentified taphonomic phenomenon in fossils from Jehol deposits.

scholarly journals The dual impact of Ostreopsis cf. ovata on Mytilus galloprovincialis and Paracentrotus lividus: Toxin accumulation and pathological aspects

2020 ◽  
Author(s):  
ANGELA SARDO ◽  
RACHELE ROSSI ◽  
VITTORIO SOPRANO ◽  
PATRIZIA CIMINIELLO ◽  
ERNESTO FATTORUSSO ◽  
...  
Keyword(s):  
Mytilus Galloprovincialis ◽  
Sea Urchins ◽  
Animal Health ◽  
Paracentrotus Lividus ◽  
Human Consumption ◽  
Natural Material ◽  
Rocky Shores ◽  
Marine Animals ◽  
Gulf Of Naples ◽  
Direct Exposure

Blooms of the toxic dinoflagellates Ostreopsis have become common along rocky shores of the Mediterranean Sea. In addition to health problems for beach-goers, Ostreopsis toxins may accumulate in benthic marine animals used for human consumption, which however at times have shown signals of stress and even mortality. In order to elucidate the actual relationships between Ostreopsis and benthic invertebrates, we exposed mussels Mytilus galloprovincialis and sea urchins Paracentrotus lividus from the Gulf of Naples to cultures and natural material of O. cf. ovata and assessed feeding and adverse effects on the animals, along with their acquired toxicity. Mussels exposed to O. cf. ovata for 24 hours filtered the microalgae at different rates, depending on both mussel size and microalgal density, and became weakly toxic in some cases. Under longer exposure most animals died and all survivors were toxic. Detoxification of a naturally toxic mussel populations from an area affected by O. cf. ovata blooms took more than two weeks. Sea urchins fed with the red alga Asparagopsis taxiformis epiphytised by O. cf. ovata did not show damages and became mildly toxic in some cases. However, the direct exposure of sea urchins to O. cf. ovata cultures caused the partial or total loss of the spines in a density-dependent way, with the death of the animals at the highest microalgal concentrations. Milder effects were registered with sonicated cultures or toxin extracts. Our results indicate that the balance between toxicity and animal health in these invertebrates depends on the mode and intensity of exposure to the toxic microalga, while the response varies between the two species but also within the same species. This scenario matches the variety of responses of benthic populations recorded in the natural environment in areas affected by O. cf. ovata blooms.

Direct evidence of trophic interaction between a large lamniform shark, Cretodus sp., and a marine turtle from the Cretaceous of northeastern Italy

2017 ◽  
Vol 469 ◽  
pp. 104-121 ◽  
Author(s):  
Jacopo Amalfitano ◽  
Fabio Marco Dalla Vecchia ◽  
Luca Giusberti ◽  
Eliana Fornaciari ◽  
Valeria Luciani ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Trophic Interaction ◽  
Marine Turtle ◽  
Northeastern Italy

Feeding habits and trophic status of Merluccius hubbsi along the northernmost limit of its distribution in the South-western Atlantic

2019 ◽  
Vol 99 (06) ◽  
pp. 1399-1408
Author(s):  
Paulo A. S. Costa ◽  
Adriana C. Braga ◽  
Giovanna S. Malavolti ◽  
Marcos A. L. Franco ◽  
Pedro V. Gatts ◽  
...  
Keyword(s):  
Total Mercury ◽  
Trophic Status ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Generalist Predator ◽  
Isotopic Niche ◽  
Benthic Fish ◽  
Ontogenetic Changes ◽  
Western Atlantic ◽  
Feeding Plasticity

AbstractStomach contents analysis and stable isotope results indicate M. hubbsi is a generalist predator that feeds mainly on demersal fishes, followed by crustaceans and cephalopods. Ontogenetic changes in diet were identified, with fish importance increasing in the diet with hake size. Smaller hake (<250 mm) fed mostly on the sepiolid Semirossia tenera (89.45%IRI) and engraulid fish (89.96%IRI). Mid-sized hake (250–300 mm) fed mainly on benthic fish such as Bellator brachychir (95.63%IRI) and euphausiids (56.46%IRI), while larger hake (>300 mm) fed heavily on Dactylopterus volitans (94.80%IRI) and occasionally on a variety of teleosts. Significant correlations between δ13C (P < 0.05), THg (P < 0.001) and hake size occurred, whereas no relationship was observed between δ15N and hake size or δ15N and total mercury. Signatures were lowest in smaller hake with a tendency of increasing with size. Smaller and larger hake were significantly different in δ13C. Differences regarding isotopic niche width were quantified for each size group; trophic diversity and trophic redundancy among them were negligible, but hake >300 mm possibly have a larger feeding plasticity due to the combination of prey from a wide trophic level range.

scholarly journals The Food of the Bottom Fauna of the Plymouth Fishing Grounds

1925 ◽  
Vol 13 (3) ◽  
pp. 560-599 ◽  
Author(s):  
O. D. Hunt
Keyword(s):  
Stomach Contents ◽  
Bottom Fauna ◽  
Marine Animals ◽  
Surrounding Water ◽  
Organic Detritus ◽  
General Application ◽  
Deposit Feeders ◽  
The Common ◽  
Micro Organisms ◽  
Natural Groups

1. The food of the bottom fauna of the Plymouth fishing-grounds, at an average depth of 27 fathoms, lias been investigated. This has been done by the examination of the stomach contents of animals, both fresh and preserved, and supplemented by observation of living animals in aquaria.2. The sources of food have been discussed. Attention is drawn to the importance in these regions, not so much of organic detritus, which is considered by Petersen and Blegvad to be the only important ultimate supply in Danish waters, but of the contributions from the plankton itself and from the considerable microflora and microfauna inhabiting the bottom deposits.3. Petersen and Boysen Jensen have stated that the detritus present in Danish waters can be traced almost entirely to the annual decay of the Zostera beds. The area occupied by Zostera in Plymouth waters is very smalLin.comparison with that in the Danish fjords and the detritus found here, though considerable in quantity, and in appearance much as described by Petersen, must originate largely from other sources. The possible1 sources of origin apart from land-sources are the coastal Algse and the plankton. A consideration of the annual production of each of these' suggests that the plankton is the more important factor.4. Blegvad has classified marine animals according to their food into Herbivores, Carnivores, and Detritus-eaters, but this classification does not fit the conditions in the area here studied and is not therefore of general application. Herbivores are absent from these grounds, and few of the animals could be described strictly as detritus-eaters. The animals fall into the following natural groups, according to their food and the mode and location of their feeding:—A. Carnivores—Animals which feed mainly upon other animals, either living or as carrion.B. Suspension-feeders—Animals which feed by selecting from the surrounding water the suspended micro-organisms and detritus.C. Deposit-feeders—Animals which feed upon the detritus deposited on the bottom, together with its associated micro-organisms.5. Following the preceding classification the food of the common animals of the Plymouth fishing-grounds has been described briefly.

scholarly journals Consumption of pelagic tunicates by cetaceans calves in the Mediterranean Sea

2018 ◽  
Author(s):  
NATALIA FRAIJA-FERNÁNDEZ ◽  
ALFONSO A. RAMOS-ESPLÁ ◽  
MARÍA ÁNGELES RADUÁN ◽  
CARMEN BLANCO ◽  
JUAN ANTONIO RAGA ◽  
...  
Keyword(s):  
Food Webs ◽  
Mediterranean Sea ◽  
Stomach Contents ◽  
Gelatinous Zooplankton ◽  
Western Mediterranean ◽  
Ecological Significance ◽  
Marine Animals ◽  
Cetacean Species ◽  
Marine Food Webs ◽  
Marine Food

Gelatinous zooplankton, including jellyfish, ctenophores and pelagic tunicates, constitutes fragile marine animals that live in the water column, and represent an important resource for marine food webs through their seasonal pulses. Although there is scarce evidence on the occurrence of gelatinous zooplankton in stomach contents of apex, endothermic predators such as cetaceans, the ecological significance of such observations requires consideration. In this study, we report on the occurrence of pelagic tunicates in the stomach of three individual calves of two cetacean species from the western Mediterranean, and collate all previous reports of gelatinous zooplankton in cetacean diets. We then briefly discuss the possible dietary significance of these observations.

scholarly journals Effects of Invasive Jumping Worms (Amynthas spp.) On Microhabitat and Trophic Interactions of Native Herpetofauna

2021 ◽  
Author(s):  
Erin Renee Crone ◽  
Erin L Sauer ◽  
Bradley M Herrick ◽  
David Drake ◽  
Daniel L Preston
Keyword(s):  
Invasive Species ◽  
Leaf Litter ◽  
Trophic Interactions ◽  
Food Resource ◽  
Stomach Contents ◽  
Acheta Domesticus ◽  
Soil Conditions ◽  
Thamnophis Sirtalis ◽  
Native Communities ◽  
Defensive Behaviors

Abstract Invasive species can affect native communities through multiple mechanisms, including ecosystem engineering and trophic interactions. In North America, invasive jumping worms ( Amynthas spp.) may alter microhabitats used by native herpetofauna or serve as a novel food resource for herpetofauna predators. We investigated effects of Amynthas on leaf litter microhabitat and trophic interactions of native herpetofauna using an outdoor mesocosm experiment, laboratory feeding trials, and field surveys of predator stomach contents in Wisconsin, USA. In mesocosms, Amynthas reduced leaf litter biomass but did not have clear effects on soil conditions (pH, moisture, and temperature) or survival of American toad metamorphs ( Anaxyrus americanus ). In laboratory trials, American toads preyed on Amynthas, though toads were less successful at capturing Amynthas compared with alternative prey, namely European earthworms ( Lumbricus spp.) and crickets ( Acheta domesticus). The differences in prey attack success were likely due to unique defensive behaviors of Amynthas . Amynthas also spent less time moving than Lumbricus , which was associated with later prey detection times by toads. Based on diet surveys, Amynthas are consumed by common garter snakes ( Thamnophis sirtalis ) in southern Wisconsin. We did not find evidence of Amynthas consumption by American toads or red-bellied snakes ( Storeria occipitomaculata ), although additional surveys will be needed to definitively determine whether these taxa are consuming Amynthas . Our findings highlight the importance of studying multiple mechanisms by which invasive species affect native communities and suggest that unique anti-predator behaviors may influence how Amynthas are incorporated into food webs as a novel prey resource.

Trophic interactions of vampire catfishes (Siluriformes: Vandelliinae) revealed by metabarcoding analysis of stomach contents

2021 ◽  
Author(s):  
Karine Orlandi Bonato ◽  
Priscilla Caroline Silva ◽  
Fernando Rogério Carvalho ◽  
Luiz Roberto Malabarba
Keyword(s):  
Trophic Interactions ◽  
Stomach Contents

scholarly journals Prey choice and cannibalistic behaviour in the theropod Coelophysis

2006 ◽  
Vol 2 (4) ◽  
pp. 611-614 ◽  
Author(s):  
Sterling J Nesbitt ◽  
Alan H Turner ◽  
Gregory M Erickson ◽  
Mark A Norell
Keyword(s):  
Histological Examination ◽  
Fossil Record ◽  
Direct Evidence ◽  
Stomach Contents ◽  
Gut Contents ◽  
Prey Choice ◽  
Cannibalistic Behaviour ◽  
Coelophysis Bauri

Abstract Direct evidence of prey choice in carnivorous dinosaurs is rare in the fossil record. The most celebrated example pertains to purported stomach contents in the carnivorous dinosaur Coelophysis bauri , which besides revealing prey choice, also points to cannibalistic behaviour as being commonplace ( Colbert 1989 , 1995). Here, we test this hypothesis by conducting the first comprehensive anatomical and histological examination of the famed Coelophysis ‘cannibals’. The results unequivocally show that the gut contents derive from early crocodylomorphs rather than juveniles of Coelophysis . These findings suggest that this taxon is not cannibalistic and bring into question the commonality of this behaviour among non-avian dinosaurs.

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