Endoparasitic helminth fauna and diet of Geophagus sveni (Pisces) in Upper Paraná River basin.

In freshwater ecosystems, parasite infection patterns are influenced by factors including spatial-temporal variations, host diet, and habitat. Fish often change diets, affecting their parasite communities. This study focused on non-native host fish Geophagus sveni, aiming to characterize diet and endoparasitic helminth fauna patterns in the invaded area, investigating spatial and seasonal possible differences of endoparasite infections and correlating with host diet, in São José dos Dourados River and Tietê River areas. The host fish were collected in these areas during the dry and rainy season using gillnets. The endoparasites were collected and preserved in alcohol and identified using taxonomic methods, and stomach contents were examined for diet analysis. Parasitism descriptors were calculated and evaluated spatially and seasonally by ANOVA and the Kruskal-Wallis tests. PERMANOVA assessed G. sveni diet differences, and RDA correlated the endohelminth abundance with the host diet. Two endoparasites were recorded: metacercariae of Austrodiplostomum compactum (Trematoda) and larvae and adults of Raphidascaris (Sprentascaris) lanfrediae (Nematoda). Spatial differences were observed for the mean abundance and prevalence of R. (S.) lanfrediae and A. compactum prevalence. Seasonal variations of parasitic descriptors occurred for the nematode in the Tietê River area. The detritus and aquatic insects were the most consumed items by G. sveni. Detritus consumption positively correlates with nematode abundance. The findings indicate that factors such as artificial channels and rainfall, which can influence resource availability, may affect the fish's diet and potentially influence the structure of its endoparasite community. The study emphasizes the importance of understanding trophic chain-transmitted parasites and calls for further research in Neotropical environments.

Invasive European green crab (Carcinus maenas) predation in a Washington State estuary revealed with DNA metabarcoding.

Predation by invasive species can threaten local ecosystems and economies. The European green crab (Carcinus maenas), one of the most widespread marine invasive species, is an effective predator associated with clam and crab population declines outside of its native range. In the U.S. Pacific Northwest, green crab has recently increased in abundance and expanded its distribution, generating concern for estuarine ecosystems and associated aquaculture production. However, regionally-specific information on the trophic impacts of invasive green crab is very limited. We compared the stomach contents of green crabs collected on clam aquaculture beds versus intertidal sloughs in Willapa Bay, Washington, to provide the first in-depth description of European green crab diet at a particularly crucial time for regional management. We first identified putative prey items using DNA metabarcoding of stomach content samples. We compared diet composition across sites using prey presence/absence and an index of species-specific relative abundance. For eight prey species, we also calibrated metabarcoding data to quantitatively compare DNA abundance between prey taxa, and to describe an 'average' green crab diet at an intertidal slough versus a clam aquaculture bed. From the stomach contents of 61 green crabs, we identified 54 unique taxa belonging to nine phyla. The stomach contents of crabs collected from clam aquaculture beds were significantly different from the stomach contents of crabs collected at intertidal sloughs. Across all sites, arthropods were the most frequently detected prey, with the native hairy shore crab (Hemigrapsus oregonensis) the single most common prey item. Of the eight species calibrated with a quantitative model, two ecologically-important native species-the sand shrimp (Crangon franciscorum) and the Pacific staghorn sculpin (Leptocottus armatus)-had the highest average DNA abundance when detected in a stomach content sample. In addition to providing timely information on green crab diet, our research demonstrates the novel application of a recently developed model for more quantitative DNA metabarcoding. This represents another step in the ongoing evolution of DNA-based diet analysis towards producing the quantitative data necessary for modeling invasive species impacts.

Metabolomics approach for predicting stomach and colon contents in dead Arctocephalus pusillus pusillus, Arctocephalus tropicalis, Lobodon carcinophaga and Ommatophoca rossii from sub-Antarctic region.

The dietary habits of seals play a pivotal role in shaping management and administration policies, especially in regions with potential interactions with fisheries. Previous studies have utilized various methods, including traditional approaches, to predict seal diets by retrieving indigestible prey parts, such as calcified structures, from intestines, feces, and stomach contents. Additionally, methods evaluating nitrogen and stable isotopes of carbon have been employed. The metabolomics approach, capable of quantifying small-scale molecules in biofluids, holds promise for specifying dietary exposures and estimating disease risk. This study aimed to assess the diet composition of five seal species-Arctocephalus pusillus pusillus, Lobodon carcinophaga, Ommatophoca rossii, and Arctocephalus tropicalis 1 and 2-by analyzing stomach and colon contents collected from stranded dead seals at various locations. Metabolite concentrations in the seal stomach and colon contents were determined using Nuclear Magnetic Resonance Spectroscopy. Among the colon and stomach contents, 29 known and 8 unknown metabolites were identified. Four metabolites (alanine, fumarate, lactate, and proline) from stomach contents and one metabolite (alanine) from colon contents showed no significant differences between seal species (p>0.05). This suggests that traces of these metabolites in the stomach and colon contents may be produced by the seals' gut microbiome or derived from other animals, possibly indicating reliance on fish caught at sea. Despite this insight, the cause of death for stranded seals remains unclear. The study highlights the need for specific and reliable biomarkers to precisely indicate dietary exposures across seal populations. Additionally, there is a call for the development of relevant metabolite and disease interaction networks to explore disease-related metabolites in seals. Ultimately, the metabolomic method employed in this study reveals potential metabolites in the stomach and colon contents of these seal species.

Body size mediates trophic interaction strength of novel fish assemblages under climate change.

Ecological similarity plays an important role in biotic interactions. Increased body size similarity of competing species, for example, increases the strength of their biotic interactions. Body sizes of many exothermic species are forecast to be altered under global warming, mediating shifts in existing trophic interactions among species, in particular for species with different thermal niches. Temperate rocky reefs along the southeast coast of Australia are located in a climate warming hotspot and now house a mixture of temperate native fish species and poleward range-extending tropical fishes (vagrants), creating novel species assemblages. Here, we studied the relationship between body size similarity and trophic overlap between individual temperate native and tropical vagrant fishes. Dietary niche overlap between vagrant and native fish species increased as their body sizes converged, based on both stomach content composition (short-term diet), stable isotope analyses (integrated long-term diet) and similarity in consumed prey sizes. We conclude that the warming-induced faster growth rates of tropical range-extending fish species at their cool water ranges will continue to converge their body size towards and strengthen their degree of trophic interactions and dietary overlap with co-occurring native temperate species under increasing ocean warming. The strengthening of these novel competitive interactions is likely to drive changes to temperate food web structures and reshuffle existing species community structures.

Influence of trophic overlaps and trophic niche amplitude on microplastic intake of fish species in shallow areas of a neotropical coastal lagoon.

Plastic pollution is a global challenge that affects all marine ecosystems, and reflects all types of uses and activities of human society in these environments. In marine ecosystems, microplastics and mesoplastics interact with invertebrates and become available to higher predators, such as fish, which can ingest these contaminants. This study aimed to analyze how ecological food interactions (diet overlap and trophic niche amplitude) among fish species contribute to the ingestion of plastic particles. The gastrointestinal contents of six fish species (Atherinella brasiliensis, Eucinostomus melanopterus, Eucinostomus argenteus, Genidens genidens, Coptodon rendalli, and Geophagus brasiliensis) were analyzed to identify prey items and plastic ingestion. Based on the ontogenetic classification, A. brasiliensis, E. melanopterus, and G. genidens were divided into juveniles and adults, and the six fish species analyzed were divided into nine predator groups. Most of the plastics ingested by the fish species were blue microplastic (MP) fibers (< 0.05 mm) classified as polyester terephthalate, polyethylene, and polybutadiene. Considering all the analyzed predators, the average number and weight of plastics ingested per individual were 2.01 and 0.0005 g, respectively. We observed that predators with a high trophic overlap could present a relationship with the intake of MP fibers owing to predation on the same resources. In addition, we observed the general pattern that when a species expands its trophic diversity and niche, it can become more susceptible to plastic ingestion. For example, the species with the highest Levin niche amplitude, E. argenteus juveniles, had the highest mean number (2.9) of ingested MP fibers. Understanding the feeding ecology and interactions among species, considering how each predator uses habitats and food resources, can provide a better understanding of how plastic particle contamination occurs and which habitats are contaminated with these polluting substances.

The impact of chronic and acute problems on sea turtles: The consequences of the oil spill and ingestion of anthropogenic debris on the tropical semi-arid coast of Ceará, Brazil.

Sea turtle mortality is often related to materials that reach the coast from different anthropic activities worldwide. This study aimed to investigate whether sea turtle mortality was related to older marine problems, such as solid waste, or one of the largest oil spill accidents on the Brazilian coast, that occurred in 2019. We posed three questions: 1) Are there solid residues in the digestive tract samples, and which typology is the most abundant? 2) Can meso­ and macro-waste marine pollutants cause mortality? 3) Is the dark material found really oil? A total of 25 gastrointestinal content (GC) samples were obtained, of which 22 ingested waste of anthropogenic origin and 18 were necropsied. These 22 samples were obtained during or after the 2019 oil spill, of which 17 specimens were affected, making it possible to suggest oil ingestion with the cause of death in the animals that could be necropsied. Macroscopic data showed that the most abundant solid waste was plastic (76.05 %), followed by fabrics (12.18 %) and oil-like materials. However, chemical data confirmed only three specimens with oil levels ranging from remnants to high. It was possible to infer possible causes of death in 16 of the total 18 necropsied cases: Most deaths were due to respiratory arrest (62.5 %), followed by pulmonary edema (12.5 %), cachexia syndrome (12.5 %), circulatory shock (6.25 %), and head trauma (6.25 %), which may have been caused by contact with solid waste, oil, or both. The study showed that not all dark material found in the GCs of turtles killed in oiled areas is truly oil, and in this sense, a chemical analysis step to prove the evidence of oil must be added to international protocols.

Pesticide Contamination Levels in the Stomach Contents of Wild Raccoons (Procyon lotor) and Masked Palm Civets (Paguma larvata) in Japan.

Pesticides, which are vital for agriculture, pose a significant threat to wildlife in transformed Japanese landscapes. Despite global reports of pesticide poisoning in animals, limited studies have examined current wildlife exposure in croplands or metropolitan areas in the region. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), our study aimed to assess the contamination status of 368 commonly used pesticides. The stomach contents of raccoons living in croplands contained 13 pesticides, including six herbicides and 11 fungicides. Neonicotinoid insecticides, some fungicides, and previously banned insecticides (benzene hexachloride and dichlofenthion) were most frequently detected and found at the highest concentrations, suggesting direct soil-plant transfer and direct consumption by crop-eating species. In masked palm civets living in metropolitan areas, four insecticides and six fungicides were detected, indicating urban wildlife exposure from raided dustbins, urban gardens, and lumber from houses. Although the maximum measured concentrations of all pesticides were lower than the acceptable daily intake for humans, it remains unclear whether these concentrations may have toxic or adverse health effects on the species evaluated in these transformed landscapes. Our study is the first to examine recent pesticide exposures in wild mammals in Japan. Application of the method we developed will lay the foundation for the examination of pesticides in other wildlife species to assist conservation management efforts in the region. Environ Toxicol Chem 2024;43:943-951. © 2024 SETAC.

Shigella sonnei utilises colicins during inter-bacterial competition.

The mammalian colon is one of the most densely populated habitats currently recognised, with 1011-1013 commensal bacteria per gram of colonic contents. Enteric pathogens must compete with the resident intestinal microbiota to cause infection. Among these enteric pathogens are Shigella species which cause approximately 125 million infections annually, of which over 90 % are caused by Shigella flexneri and Shigella sonnei. Shigella sonnei was previously reported to use a Type VI Secretion System (T6SS) to outcompete E. coli and S. flexneri in in vitro and in vivo experiments. S. sonnei strains have also been reported to harbour colicinogenic plasmids, which are an alternative anti-bacterial mechanism that could provide a competitive advantage against the intestinal microbiota. We sought to determine the contribution of both T6SS and colicins to the anti-bacterial killing activity of S. sonnei. We reveal that whilst the T6SS operon is present in S. sonnei, there is evidence of functional degradation of the system through SNPs, indels and IS within key components of the system. We created strains with synthetically inducible T6SS operons but were still unable to demonstrate anti-bacterial activity of the T6SS. We demonstrate that the anti-bacterial activity observed in our in vitro assays was due to colicin activity. We show that S. sonnei no longer displayed anti-bacterial activity against bacteria that were resistant to colicins, and removal of the colicin plasmid from S. sonnei abrogated anti-bacterial activity of S. sonnei. We propose that the anti-bacterial activity demonstrated by colicins may be sufficient for niche competition by S. sonnei within the gastrointestinal environment.

Marine turtles as bio-indicators of plastic pollution in the eastern Mediterranean.

The loggerhead turtle (Caretta caretta) has been suggested as a bio-indicator species for plastic pollution. However, detailed investigations in the eastern Mediterranean are limited. Here, we present data from loggerhead turtles (2012-2022; n = 131) of which 42.7 % (n = 57) had ingested macroplastic (pieces ≥ 5 mm). Frequency of occurrence (%) was not found to have changed over time, with body size (CCL cm), between stranded or bycaught turtles, or with levels of digesta present. The characteristics of ingested plastic (n = 492) were largely sheetlike (62 %), clear (41 %) or white (25 %) and the most common polymers identified were Polypropylene (37 %) and Polyethylene (35 %). Strong selectivity was displayed towards certain types, colours and shapes. Data are also presented for posthatchling turtles (n = 4), an understudied life stage. Much larger sample sizes will be needed for this species to be an effective bio-indicator, with the consideration of monitoring green turtles (Chelonia mydas) for the eastern Mediterranean recommended allowing a more holistic picture to be gathered.

Quantitative description of six fish species' gut contents and prey abundances in the Baltic Sea (1968-1978).

The dataset presents a compilation of stomach contents from six demersal fish species from two functional groups inhabiting the Baltic Sea. It includes detailed information on prey identities, body masses, and biomasses recovered from both the fish's digestive systems and their surrounding environment. Environmental parameters, such as salinity and temperature levels, have been integrated to enrich this dataset. The juxtaposition of information on prey found in stomachs and in the environment provides an opportunity to quantify trophic interactions across different environmental contexts and investigate how fish foraging behaviour adapts to changes in their environment, such as an increase in temperature. The compilation of body mass and taxonomic information for all species allows approaching these new questions using either a taxonomic (based on species identity) or functional trait (based on body mass) approach.

Increased Attenuation of Intestinal Contents at CT Indicates Bowel Necrosis in Closed-Loop Small Bowel Obstruction.

Background Preoperative recognition of irreversible bowel necrosis is important, as it provides valuable guidance for surgical strategy selection but also may inform perioperative risk assessment and communication. Few studies have focused on the association between CT signs and bowel necrosis. Purpose To assess the diagnostic accuracy of CT signs to predict bowel necrosis in patients with closed-loop small bowel obstruction (CL-SBO). Materials and Methods This retrospective single-center study included patients who were surgically confirmed to have CL-SBO caused by adhesion or internal hernia between January 2016 and May 2022. Necrosis was determined based on surgical exploration and postoperative pathologic examination. Two radiologists independently reviewed CT signs by both subjective visual assessment and objective measurement. Disagreements were resolved in consensus with a third gastrointestinal radiologist. Univariable and multivariable analyses were used to assess the association between CT signs and bowel necrosis, and Cohen κ was used to assess interobserver agreement. Sensitivity and specificity were calculated for each CT sign. Results This study included 145 patients: 61 (42.1%) in the necrotic group (median age, 62 years [IQR, 51-71.5 years]; 37 [60.7%] women) and 84 (57.9%) in the nonnecrotic group (median age, 61.5 years [IQR, 51-68.8 years]; 51 [60.7%] women). Univariable analysis and multivariable analysis showed that increased attenuation of intestinal contents and increased attenuation of intestinal wall were independent predictors for bowel necrosis (odds ratio = 45.3 and 15.1; P = .001 and P < .001, respectively). Increased attenuation of intestinal contents and increased attenuation of intestinal wall had similar sensitivity (64% and 67%, respectively) and specificity (99% and 92%, respectively) for predicting bowel necrosis. However, interobserver agreement was better for assessing the contents than the wall (κ = 0.84 and 0.59, respectively). Conclusion Increased attenuation of intestinal contents was a highly specific CT sign with good reproducibility to predict bowel necrosis in CL-SBO. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Taourel and Zins in this issue.

A suicide case of liquid nicotine intoxication.

A man in his 50 s, who was found vomiting and in a disturbed state when the emergency medical team arrived, then went into cardiopulmonary arrest during transport and died without responding to resuscitation. The hospital initially suspected that the death may have been caused by internal causes, but since the deceased had previously been transported to the hospital in a suicide attempt, the hospital called police regarding suspicions of unnatural death. The police investigation revealed two empty bottles of nicotine liquid for e-cigarettes in his house and a search history of "nicotine suicide" on his cellphone. In a forensic autopsy, he was found to be highly obese, and abundant fat deposits were observed in his organs. A stent was placed in the aorta, but no abnormality was found. There was no obvious stenosis or obstruction in the coronary arteries. Drug screening using liquid chromatography tandem mass spectrometry (LC-MS/MS) was performed on cardiac blood, urine, and stomach contents collected at autopsy, which revealed the presence of some medical products such as aripiprazole, nicotine, and cotinine. Further quantitative testing revealed high concentrations of nicotine in all samples. The left and right femoral venous blood concentrations were above the lethal dose, suggesting that arrhythmia or respiratory failure due to nicotine intoxication was the cause of death. With the widespread use of e-cigarettes, high concentrations of nicotine are readily available, and case reports of serious nicotine addiction are increasing. It is important to always consider addiction when conducting forensic evaluations in the medical field.

Synthesis and quantification of short-chain fatty acid esters of hydroxy fatty acids in rat intestinal contents and fecal samples by LC-MS/MS.

Short-chain fatty acid esters of hydroxy fatty acids (SFAHFAs) are a new class of endogenous lipids belonging to the fatty acid esters of the hydroxy fatty acid family. We previously uncovered their chemical structure and discussed their potential biological significance. We anticipate an increased need for SFAHFA measurements as markers of metabolic and inflammatory health. In this study, we synthesized sixty isomeric SFAHFAs by combining 12 hydroxy fatty acids (C16-C24) and five short-chain fatty acids (C2-C6) including a labelled internal standard. SFAHFA enrichment was achieved by solid-phase extraction and established a sensitive method for their quantitation by targeted LC-MS/MS. The method was applied to profile SFAHFAs in intestinal contents and fecal samples collected from rats fed a high-fat diet (HFD). The results demonstrated a significant decrease in SFAHFAs in the intestinal contents of the HFD group compared with the control group. The fecal time course (0-8 weeks) profile of SFAHFAs showed significant downregulation of acetic and propanoic acid esters in just 2 weeks after HFD administration. This study offers the first synthesis and quantitation method for SFAHFAs, demonstrating their potential use in elucidating SFAHFA sources, their role in various diseases, and potential biochemical signalling pathways.

Microplastics in the stomach content of the commercial fish species Scomber colias in the Gulf of Cadiz, SW Europe.

Concerning microplastics (MPs) contamination is increasing due their negative impacts on marine food webs and their potential toxicity to wildlife and humans. In this study, we analyze the presence of MPs in the stomachs of the commercial fish species Scomber colias (Atlantic chub mackerel) in the Gulf of Cadiz (GoC). Out of the 104 analyzed stomachs, 90.4 % contained some type of MPs, with an average of 5.4 MPs per individual. Of the 1152 MPs analyzed, 91.1 % were fibers, and 8.9 % fragments type. Fourier Transformation Infrared Spectrometry analysis was performed on 152 items, revealing that 73.6 % were MPs. The most common synthetic polymers found were polyamide (64 %), polypropylene (15 %), polystyrene (12 %), polyvinyl chloride (5 %), and polyethylene (4 %). The consistent ingestion of synthetic polymers by the individuals of Atlantic chub mackerel across different zones might suggest an even distribution of MP contamination throughout the GoC.

Effects of fermented rapeseed meal on performance, intestinal morphology, the viscosity of intestinal content, phosphorus availability, and egg quality of laying hens.

Fermented rapeseed meal has the potential to partial replace soybean meal in feed mixtures for poultry without a negative impact on the health condition and performance of birds. This is due to the fact that the fermentation process can reduce the amount of antinutritional factors, improve the use of nutrients and impart probiotic properties to rapeseed meal. Therefore, this study was undertaken to investigate the effect of fermented rapeseed meal on the performance, egg quality, intestinal morphometry, the viscosity of intestinal content and total phosphorus availability. A total of 108 Lohmann Brown laying hens at 26 wk of age were used in the 90-day study. All hens were randomly divided into 3 treatment groups, with 12 replicates (cages) each, as follows: control group received no rapeseed meal, the URSM group received 3% unfermented rapeseed meal and the FRSM group received 3% fermented rapeseed meal. In the case of performance, egg traits, sensory evaluation of eggs, the viscosity of intestinal content and the availability of total phosphorus, if the distribution was normal, a 1-way analysis of variance was performed. If the distribution was not normal, the Kruskal-Wallis test was performed. In the case of histomorphometric evaluation of the intestine, if the distribution was normal, the Student t test for independent samples was performed. If not, a Mann-Whitney U test was performed. The performed analyses showed that the supplementation of fermented rapeseed meal had no negative effect on the performance of birds and the quality of eggs. Fermented rapeseed meal was also associated with improved histomorphometric parameters of the small intestine compared to the group receiving unfermented rapeseed meal in the feed. Laying hens from FRSM group were characterized by significantly lower viscosity of intestinal content (P < 0.05) compared to URSM group. Phosphorus in FRSM group was significantly more available to the birds (P < 0.05) compared to URSM group. These results suggest that supplementation with fermented rapeseed meal may be beneficial, especially in times of unstable prices of soybean meal and problems with its availability.

Detection of chromosome-mediated blaNDM-1-carrying Aeromonas spp. in the intestinal contents of fresh water river fish in Ho Chi Minh City, Vietnam.

The spread of antibiotic-resistant bacteria is a global problem that should be addressed through the perspective of the "one health" concept. The purpose of this study was to determine the contamination rate of antibiotic-resistant Aeromonas spp. in fresh water river fish purchased from a fish market in Vietnam. We then defined the pattern of antibiotic resistance to assess antibiotic-resistant contamination. Antibiotic-resistant Aeromonas spp. were detected in the intestinal contents of 32 of 80 fish. blaNDM-1 was detected in seven strains. Extended-spectrum ß-lactamase and AmpC ß-lactamase-related genes were detected in 28 strains, including blaCTX-M-55, blaCTX-M-15, blaCTX-M-1, and blaDHA,blaFOX, and blaMOX. The blaNDM-1 detected in the seven Aeromonas spp. strains were found chromosomally. This finding suggests that the blaNDM gene is stable in the natural environment and may spread widely into animals and humans via Aeromonas spp. with a transposon. Our results suggest the importance of continuing to monitor carbapenemase genes in Aeromonas spp. to evaluate the possibility that they may spread in other Enterobacterales, and to elucidate the mechanism of spread.

Evaluation of the 'Sip Til Send' regimen before elective caesarean delivery using bedside gastric ultrasound: A paired cohort pragmatic study.

BACKGROUND: Pre-operative fasting is routinely advocated to avoid pulmonary aspiration. The European Society of Anaesthesiology and Intensive Care (ESAIC) recommends a fasting period of 2 h for liquids before surgery. Liberal drinking policies such as the 'Sip Til Send' are a suggested alternative to maintain hydration before surgery. OBJECTIVES: To compare residual gastric volumes in fully fasted nonlabouring parturients before elective caesarean delivery with the 'Sip Til Send' with water liberal drinking protocol. Our hypothesis was the 'Sip Til Send' would be noninferior to standard fasting at minimising the residual gastric volume immediately before surgery. DESIGN: A paired cohort prospective observational pragmatic study using gastric ultrasound, analysed by an operator blinded to the fasting status of each scan. SETTING: A tertiary maternity hospital in Dublin, Ireland. The study was conducted between January and June 2023. PARTICIPANTS: Pregnant women about to undergo elective caesarean delivery who had followed ESAIC fasting guidelines before admission. INTERVENTIONS: Each participant underwent two pairs (semi-recumbent and the semi-recumbent right lateral positions) of standardised ultrasound examinations of the gastric antrum: the order of these scans was randomised. The first pair of scans occurred on admission before the 'Sip Til Send' protocol commenced, the other pair just before spinal anaesthesia for caesarean delivery, after a variable time following the 'Sip Til Send' protocol. MAIN OUTCOME MEASURE: The primary outcome was the difference in antral cross-sectional area (CSA) between the fully fasted women on admission and the same women after following the 'Sip Til Send' protocol until just before spinal anaesthesia. RESULTS: Fifty-eight women were randomised for the study: 55 and 54 scans in the semi-recumbent position on admission, and 55 and 54 scans in the right lateral position just before spinal anaesthesia. The mean differences (95% CI) in CSA in the semi-recumbent and RL positions were 0.07 (-0.39 to 0.53) cm 2 and 0.04 (-0.60 to 0.68) cm 2 , respectively. Since the of 95% CIs did not cross the predefined noninferiority margin of 0.88 cm 2 , 'Sip Til Send' was noninferior to fully fasting in in terms of the antral CSA. CONCLUSION: The 'Sip Til Send' protocol of liberal hydration with water was noninferior to standard fasting prior to elective caesarean delivery. TRIAL REGISTRY NUMBER: NCT05783427 ClinicalTrials.gov.

Trophic ecology of Acestrorhynchus falcirostris Cuvier, 1819 in island lakes on the lower stretch of the Solimões River, Amazon Basin / Ecologia trófica de Acestrorhynchus falcirostris Cuvier, 1819 em lagos de ilha no trecho inferior do Rio Solimões, Bacia Amazônica

Abstract The aim objective of this study was to determine the trophic ecology of juvenile and adult Acestrorhynchus falcirostris during the rising and flood (high-water) period in six island lakes adjacent to the Solimões River. As such, we investigated: i) the trophic position, through the fractional trophic niche; ii) the niche breadth; iii) niche overlap and iv) the food strategy of the species. The specimens were collected during the years 2014 to 2017, using gillnets with mesh sizes ranging from 30 to 120mm between opposite knots. Through the analysis of stomach contents, the preference in the consumption of items of animal origin was observed. Juveniles consumed insects in greater proportions (IAi% = 50%), while adults consumed fish (IAi%=99,98%). Despite the large supply of food items available in the high-water period, juveniles were the only ones to consume items of allochthonous origin, such as insects. Juveniles presented a different dietary strategy and dietary composition to adults. Juveniles were omnivores with a generalist strategy, while adults were piscivores with a specialist strategy. Thus, the food composition, niche breadth, trophic position and feeding strategy of Acestrorhynchus falcirostris change due to the stage of development.

Resumo O objetivo deste estudo foi determinar a ecologia trófica de juvenis e adultos de Acestrorhynchus falcirostris durante o período de enchente e cheia em seis lagos de ilha adjacentes ao rio Solimões. Assim, investigamos: i) a posição trófica, através do nicho trófico fracional; ii) a largura de nicho; iii) sobreposição de nicho; iv) a estratégia alimentar. Os espécimes foram coletados durante os anos de 2014 a 2017, utilizando redes de emalhar com malha variando de 30 a 120mm entre nós opostos. Por meio da análise do conteúdo estomacal, observamos a preferência no consumo de itens de origem animal. Os juvenis consumiram insetos em maiores proporções (IAi% = 50%), enquanto os adultos consumiram preferencialmente peixes (IAi% = 99,98%). Apesar da grande oferta de alimentos disponíveis no período da cheia, os juvenis eram os únicos a consumir itens de origem alóctone, como por exemplo, os insetos. Os juvenis apresentaram uma estratégia alimentar e composição alimentar diferente para os adultos. Os juvenis foram considerados onívoros com uma estratégia generalista, enquanto os adultos foram considerados piscívoros com uma estratégia alimentar mais especialista. Assim, a composição alimentar, amplitude do nicho, posição trófica e a estratégia alimentar de Acestrorhynchus falcirostris muda em função do estágio de desenvolvimento.

Exceptionally preserved stomach contents of a young tyrannosaurid reveal an ontogenetic dietary shift in an iconic extinct predator.

Tyrannosaurids were large carnivorous dinosaurs that underwent major changes in skull robusticity and body proportions as they grew, suggesting that they occupied different ecological niches during their life span. Although adults commonly fed on dinosaurian megaherbivores, the diet of juvenile tyrannosaurids is largely unknown. Here, we describe a remarkable specimen of a juvenile Gorgosaurus libratus that preserves the articulated hindlimbs of two yearling caenagnathid dinosaurs inside its abdominal cavity. The prey were selectively dismembered and consumed in two separate feeding events. This predator-prey association provides direct evidence of an ontogenetic dietary shift in tyrannosaurids. Juvenile individuals may have hunted small and young dinosaurs until they reached a size when, to satisfy energy requirements, they transitioned to feeding on dinosaurian megaherbivores. Tyrannosaurids occupied both mesopredator and apex predator roles during their life span, a factor that may have been key to their evolutionary success.

Notes on stomach contents of pygmy and dwarf sperm whales (Kogia spp.) from around Japan.

The diets of pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales in Japanese waters are poorly known. We report new information on the diets of these two species from these waters based on identifiable hard-part remains recovered from the stomach contents of 29 whales (11 pygmy and 18 dwarf sperm whales) that stranded between 1991 and 2021; those of a further two dwarf sperm whales were empty. The cephalopod (and secondarily fish and crustacean) component of the diets of these 29 whales, based on analysis of identifiable stomach-content remains, is described. The main prey includes cephalopods, represented by 1556 identifiable lower beaks (and 1483 upper beaks), crustaceans (represented by heavily digested, unidentifiable remains), and fishes (as represented by 92 otoliths). Identified prey comprises 30 species from 16 cephalopod families and 5 families from 5 fish orders. Oceanic cephalopods are the main prey of both whale species, particularly Enoploteuthis (Paraenoploteuthis) chunii and Chiroteuthis (Chirothauma) picteti. Prey diversity index values (Shannon-Weaver's diversity index H') are 2.41 for the pygmy sperm whale and 2.66 for the dwarf sperm whale. Although the main cephalopod component in the diets of these two whale species is similar, Pianka's index (0.40), a measure of niche overlap, is not that high, and may be influenced by differences in prey dominance in different feeding areas.