Deliberate Feeding Research Articles

Single-cell hemoprotein (heme-SCP) exerts the prebiotic potential to establish a healthy gut microbiota in small pet dogs

To investigate the effect of the single-cell hemoprotein (heme-SCP) source on animals, a dog-treat (100 g for each dog) harboring 0.2% heme-SCP was manufactured and fed to seven pet dogs (< 10 kg) in a randomized manner (irrespective of owner’s feeding style, dogs’ health conditions, and staple diets), and the feces before and after the dog-treat diet were analyzed to define the structure of the microbiota. The total bacterial species of the seven dogs showed no difference (564–584), although the bacterial compositions varied significantly. The Firmicutes phylum increased (54.7–73.7%), showing differential species composition before and after heme-SCP intake. Proteobacteria, Bacteroidetes, and Fusobacteria decreased (5.4–3.8%, 32.9–16.8%, and 6.3–3.6%, respectively), which agreed with the previous observation of deliberate feeding. Therefore, it is conceivable that heme-SCP as a prebiotic can shape the gut microbiota regardless of the administration method.

Capture of conspecific planktonic larvae by the suspension-feeding gastropodCrepipatella peruviana: association between adult and larval size

ABSTRACTFree-living, planktonic larvae can be vulnerable to capture and ingestion by adult suspension-feeders. This is particularly the case for larvae that settle gregariously in benthic environments where suspension-feeders occur at high densities. Larvae of gregarious suspension-feeding species are at particularly high risk, as adults of their own species often serve as cues for metamorphosis. We conducted laboratory experiments to assess the extent to which adults of the suspension-feeding caenogastropod Crepipatella peruviana would capture and ingest their own larvae. Experiments were conducted with adults of different sizes, with larvae of different ages and sizes, and in the presence or absence of phytoplankton. Adults captured larvae in all experiments. The presence of microalgae in the water did not influence the extent of larval capture. On average, 39% of larvae were captured during the 3-h feeding periods, regardless of adult size. However, up to 34% of the larvae that were captured on the gill were later discarded as pseudofaeces; the other 64% were ingested. The extent of capture by adults was not related to adult size, or to larval size and, thus, to larval age. Our results suggest that the filtration of congeneric larvae by adult C. peruviana is a result of accidental capture rather than a deliberate feeding preference. Such ingestion could, however, still be an important source of larval mortality, especially when the advanced larvae of this species are searching for a suitable substrate for metamorphosis.

PATTERNS OF UNREPAIRED SHELL DAMAGE IN RECENT BRACHIOPODS FROM FIORDLAND (NEW ZEALAND)

In order to provide quantitative data concerning patterns of shell breakage and repair in rhynchonelliform brachiopods, we studied undisturbed death assemblages from a New Zealand fiord complex where three species of terebratulide and one rhynchonellide occur in dense mixed patches on the near vertical walls. Proportions of damaged (both repaired and non-repaired) individuals varied between both taxa and sampling site. However, the general observation was that few individuals show signs of having been able to repair damage but the proportion of individuals showing unrepaired, and hence presumably fatal, breakages was higher (up to 76% in Magasella sanguinea from one sample from Tricky Cove in Doubtful Sound). Damage was mostly concentrated around the anterior margins and affected both valves and is consistent with having been clamped between a set of either jaws or claws. Potential culprits include fish (wrasse), rock lobsters and echinoids. As yet it is unclear whether the damage results from deliberate feeding activity or as collateral damage from grazers feeding on other organisms on the fiord walls which may allow secondary predation by asteroids. The net effect is, however, the same, in that the damage appears to have been fatal. More structured sampling is now required to understand the spatial variation in this damage and mortality, and also to establish the culprits with more certainty.

Supplementary feeding and endoparasites in threatened avian scavengers: Coprologic evidence from red kites in their wintering stronghold

Many obligate and facultative avian scavengers are increasingly dependent on food provided in supplementary feeding stations (SFS), which are managed for the conservation of these species. Deliberate feeding can influence disease-related host demography and population dynamics through physiological changes and density-dependent parasite acquisition and transmission, but information on this threat to avian scavengers is scarce. Due to their effects on host aggregation and density, we hypothesised that the predictability and concentration of food in SFS can exacerbate parasite infection. This hypothesis was tested by comparing the prevalence, richness, abundance and mixed infection of endoparasites (coccidia and helminths) in red kites Milvus milvus foraging on livestock carcasses (mostly of pigs and poultry) in overcrowded and confined conditions at SFS, relative to those foraging alone or in small groups on wild prey unevenly randomly distributed within large areas during winter, mostly wild rabbits (Oryctolagus cuniculus). No clear differences were found between areas with and without SFS in the prevalence and abundance of oocyst of Eimeria. This coccidian genus appears to include parasites of the prey rather than the raptors, thus representing parasite transport or pseudo-parasitism rather than actual parasitism in the kites. A higher prevalence and richness of helminths, as well as mixed infections with several phyla, was found in kites exploiting SFS than in those feeding on wild prey in the area without SFS. The unsanitary conditions derived from the stack of livestock carcasses and the contamination of carrion with the faeces of multiple scavenger hosts can increase the accumulation and persistence of helminths eggs and intermediate hosts. The regular use and frequent confinement of large numbers of red kites at SFS can promote the spread of parasites to a large proportion of the European breeding population distributed across Spain during the winter. We encourage that carcasses of free roaming livestock can be left in the countryside, as well as the conservation management of wildlife exploited as food by red kites (especially wild rabbits), to attempt avoiding overcrowded and confined conditions at SFS. Further research is required to assess the impact of deliberate feeding on the spread of parasites and other disease agents in the threatened species SFS are intended to favour.

Herbivorous fishes Siganus rivulatus (Siganidae) and Zebrasoma desjardinii (Acanthuridae) feed on Ctenophora and Scyphozoa in the Red Sea

Individuals of the rabbitfish Siganus rivulatus (Siganidae) and surgeonfish Zebrasoma desjardinii (Acanthuridae) were observed feeding on ctenophores and scyphozoans in the northern Red Sea during late spring and early summer seasons between 2010 and 2015. Siganus rivulatus and Z. desjardinii, considered nominally herbivorous, preyed on relatively large ctenophores until disintegration, and on the moon jellyfish Aurelia aurita (Scyphozoa) until they sank to the bottom. Siganus rivulatus was the most dominant predatory fish feeding on gelatinous zooplankton (37 % of attacks on ctenophores and 51 % of attacks on A. aurita). Furthermore, prey individuals were usually approached by two or more fish simultaneously. Eleven additional fish species fed on gelatinous zooplankton, with Chaetodon fasciatus (Chaetodontidae) accounting for 27 and 12 % of the attacks on ctenophores and A. aurita, respectively, and Z. desjardinii for 17 and 24 % of the attacks. Other fishes attacked gelatinous zooplankton in ≤6 % of the observations. This study constitutes the first record of S. rivulatus and Z. desjardinii preying on ctenophores and also confirms preliminary observations of S. rivulatus feeding on scyphozoans. Although herbivorous fishes may accidentally ingest small invertebrates while feeding on algae, the deliberate feeding on gelatinous zooplankton observed for S. rivulatus and Z. desjardinii suggests that their trophic role should be reevaluated.

In Situ Observations during Chemical Vapor Deposition of Hexagonal Boron Nitride on Polycrystalline Copper.

Using a combination of complementary in situ X-ray photoelectron spectroscopy and X-ray diffraction, we study the fundamental mechanisms underlying the chemical vapor deposition (CVD) of hexagonal boron nitride (h-BN) on polycrystalline Cu. The nucleation and growth of h-BN layers is found to occur isothermally, i.e., at constant elevated temperature, on the Cu surface during exposure to borazine. A Cu lattice expansion during borazine exposure and B precipitation from Cu upon cooling highlight that B is incorporated into the Cu bulk, i.e., that growth is not just surface-mediated. On this basis we suggest that B is taken up in the Cu catalyst while N is not (by relative amounts), indicating element-specific feeding mechanisms including the bulk of the catalyst. We further show that oxygen intercalation readily occurs under as-grown h-BN during ambient air exposure, as is common in further processing, and that this negatively affects the stability of h-BN on the catalyst. For extended air exposure Cu oxidation is observed, and upon re-heating in vacuum an oxygen-mediated disintegration of the h-BN film via volatile boron oxides occurs. Importantly, this disintegration is catalyst mediated, i.e., occurs at the catalyst/h-BN interface and depends on the level of oxygen fed to this interface. In turn, however, deliberate feeding of oxygen during h-BN deposition can positively affect control over film morphology. We discuss the implications of these observations in the context of corrosion protection and relate them to challenges in process integration and heterostructure CVD.

The growth of ‘botos feeding tourism’, a new tourism industry based on the boto (Amazon river dolphin) Inia geoffrensis in the Amazonas State, Brazil

The Amazon’s reputation and ability to draw tourists is strongly associated with the natural environment and with tourist’s ability to sight and interact with iconic animals. In Brazil, four cases of aggregations of wild boto (Amazon River dolphin; Inia geoffrensis), becoming conditioned to human contact through food provisioning are occurring in Amazonas State, Central Amazon, where tourists can feed, touch and swim with the botos. The feeding of wild dolphins imposes significant risks, both for the dolphins and for the tourists, and these dangers are evident at Novo Airao City, which is the longest established of the four mentioned cases. There are few rules imposed, inadequate infrastructure and no specialized employee training or surveillance. Competitive, aggressive interactions between dolphins, pushing, ramming and biting are common and a number of dangerous interactions between the dolphins and tourists have been observed. It is evident that the establishment of this tourist-dolphin interaction is facilitated by the deliberate feeding of the dolphins and that this activity has become financially lucrative for local people. Despite bringing benefits to the region, the growth of this ‘botos feeding tourism’ activity in the Amazon is currently poorly managed and there is a high risk of injury or fatality if interactions continue to develop without improved and careful management.

Bioaccumulation of cyanuric acid in edible tissues of shrimp following experimental feeding

Due to concerns that cyanuric acid (CYA)-contaminated feed had been used in aquaculture and could enter the human food chain, a method to quantify CYA residues in the edible tissues of fish and shrimp was previously developed and validated. This paper provides further data on the deliberate feeding of CYA to shrimp to determine the extent of residue accumulation in edible tissue. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) was employed for the analysis of CYA in shrimp tissue. Edible tissue of shrimp fed 1666 or 3333 mg kg−1 CYA in their diet (approximately 55 and 124 mg kg−1 body weight) contained 0.767 and 0.406 mg kg−1 CYA, respectively. The residue levels are below the World Health Organization (WHO) tolerable daily intake level for CYA and are generally considered unlikely to pose a human health risk.

First experiences with free‐ranging giant day geckos (Phelsuma madagascariensis grandis, Gray 1870) in the masoala rainforest exhibit in Zurich Zoo, Switzerland

AbstractSixty giant day geckos (Phelsuma madagascariensis grandis) have been introduced into the Masoala rainforest exhibit of Zurich Zoo. Eighteen geckos were monitored during a 3‐month study using the telemetry method. In general, the geckos were able to adapt well under these semi‐natural conditions of the exhibit. The geckos accessed to nearly all locations in the exhibit; some of the animals remained stationary, whereas others covered dozens of meters within a week. They preferred four species of plants as well as the artificial structures supporting the walls and roof of the exhibit, and displayed natural behaviors. Animals were observed feeding on all kind of arthropods and nectar substances, and also on food items dropped from feeding stations for other species. Deliberate feeding targeted at the geckos was finally reduced to a calcium‐rich squash along the visitor's main path. Reproduction was observed frequently within the exhibit. These findings suggest that the geckos will be able to build up a self‐sustaining population and contribute to a nearly‐authentic experience for zoo visitors. Zoo Biol 0:1–7, 2006. © 2006 Wiley‐Liss, Inc.

SCAVENGING BY SNAKES: AN EXAMINATION OF THE LITERATURE

Although it is widely known that most species of snakes readily accept carrion in captivity, the notion of scavenging by wild snakes historically has been rejected or ignored. Herein, we review the literature describing instances of scavenging by snakes and consider the implications of carrion use on their ecology. Thirty-nine published accounts yielded 50 observations of scavenging by snakes (43 from field observations and seven from laboratory studies). Thirty-five species from five families were represented, but pitvipers and piscivorous snakes were represented more frequently than other groups. Scavenged material varied widely and included rodents, birds, fish, frogs, and snakes. Olfaction appears to be the overriding sensory modality used for carrion detection. Some species may use scavenging as a deliberate feeding strategy that supplements their regular modes of prey acquisition. Additional knowledge of the scavenging behavior of snakes should provide new insights into the fundamentals of the ecolo...

Avian spatial segregation at edges and interiors of urban parks in Madrid, Spain

Few studies have investigated the effects of urban landscape composition on avian habitat selection at urban-park edges. I assessed how the number of species, density of guilds, and density of individual species varied between edge and interior habitats in six large wooded parks in Madrid (Spain), and analysed such patterns in relation to habitat structure, car traffic, and pedestrian traffic. Few differences in habitat structure were found; whereas car and pedestrian traffic were significantly higher at edges. Species foraging in trees and on the ground, and nesting in trees and in tree cavities had lower numbers and breeding densities at edges, probably as a result of the disturbance from traffic noise and pedestrians. Species highly habituated to human activities (House Sparrows Passer domesticus and Rock Doves Columba livia) displayed opposite patterns, with higher breeding densities at urban-park edges, probably due to their higher foraging opportunities (refuse, people leftovers, deliberate feeding) and nest site availability in adjacent buildings. Urbanisation sprawl may increase the prevalence of edge specialists and diminish the representation of species with specific habitat requirements.

Porosity in base metal partial denture casting alloys, related industrial alloys, and pure metals

Two types of specimens were cast from a variety of pure metals and alloys. A unidirectional solidification system was used for the production of the first, whilst a deliberate feeding problem was incorporated in the production of the second. The specimens were subjected to radiographic and metallographic evaluation in conjunction with porosity determinations, in order to ascertain how the amount and pattern of porosity varied with alloy complexity and alloy composition.

Food testing in allergy. Intradermal provocative vs deliberate feeding.

The results of 1500 intradermal provocative tests and 193 deliberate feeding tests in 121 patients indicated that 17.6% of the intradermal provocative tests were positive; however, 37.8% of these positive tests were not confirmed by deliberate feeding tests. The frequency of occurrence of the positive tests, in foods tested, was tabulated. The question is raised as to whether a series of patients with known food allergy would test positive in a reliable way with intradermal provocative food test when compared to testing a series of control nonallergic patients or testing reacting patients with a placebo control.

ROENTGEN STUDIES OF PATIENTS WITH GASTRO-INTESTINAL FOOD ALLERGY

Roentgen studies of disturbances in the muscular tone and peristaltic activity in the gastro-intestinal tract originating from food allergy will be considered in this contribution. Previously, little attention has been paid to such disturbances. A few interesting observations, however, have been recorded. Crispin, 1 in 1915, in his study of a patient who had suffered from angioneurotic edema, associated with abdominal pain and hematemesis, observed by roentgen ray a lesion near the pylorus, which was found at operation to be due to angioneurotic edema. This is now recognized as an allergic condition. Eyermann 2 in 1927 published the only previous roentgen study of the results of deliberate feeding of an allergenic food on the function of the gastro-intestinal tract. His patient, a woman, aged 35, had had urticaria, epigastric burning, regurgitation, hiccups, alternating constipation and diarrhea, abdominal colic, pain in the upper right part of the abdomen and much intestinal