Feeding studies take guts – critical review and recommendations of methods for stomach contents analysis in fish

Journal of Fish Biology, Journal Year: 2019, Volume and Issue: 95(6), P. 1364 - 1373

Published: Oct. 7, 2019

Abstract Studies on the feeding ecology of fish are essential for exploring and contrasting trophic interactions population community dynamics within among aquatic ecosystems. In this respect, many different methods have been adopted analysis stomach contents. No consensus has, however, reached a standardised methodology despite that several decades there has an ongoing debate about which methodical approaches should be preferred. Here, we critically review scrutinise methods, addressing their strengths weaknesses emphasising inherent problems possible pitfalls in use. Although our critical assessment reveals no completely ideal approach exists, appropriate reliable procedures can through careful considerations implementation. particular, advocate objectives require choice method therefore closely linked to research questions addressed. For standardisation recommend combination relative‐fullness presence–absence as optimal commonly applied studies relative dietary composition terms prey diversity abundance. Additionally, gravimetric related quantification food consumption rates numerical selection studies. DNA‐based provides new promising complementary visual examination contents, although some technical challenges still exist. The suggested facilitates comparisons across species, ecosystems time will enhance applicability benefits research.

Language: Английский

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Studying animal niches using bulk stable isotope ratios: an updated synthesis

Oecologia, Journal Year: 2020, Volume and Issue: 193(1), P. 27 - 51

Published: May 1, 2020

Language: Английский

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The impacts of climate change on fish growth: A summary of conducted studies and current knowledge

Ecological Indicators, Journal Year: 2020, Volume and Issue: 121, P. 106976 - 106976

Published: Oct. 4, 2020

Global climate change is increasingly and profoundly threatening fishes, resulting in an uncertain future for both wild fish diversity global fisheries. Understanding how growth responds to changing environments essential indicating predicting the impacts of on populations, communities, even aquatic ecosystems, but knowledge this topic remains incomplete, some findings are contradictory. This study aimed review status current research by analysing data environment, species, response patterns from 1187 documents published 1976 2018, which helped identify key questions that currently neglected potential reasons these divergences. The results found 75% studies were conducted field (mostly temperate subtropical zones), while remainder controlled experiments. Fishes freshwater ecosystems relatively less studied than their marine counterparts. Less 1% recorded species (309 vs. approximately 35,000) 30 orders have been examine responses change. All fishes Actinopterygii. top three Perciformes, Cypriniformes, Salmoniformes number, was most frequently order. common habitat type pelagic, followed demersal reef-associated habitats. Small undervalued systems. mean trophic levels 3.2 3.4 fish. Carnivores dominant guild overall effects (primarily temperature variables) (reflected physiology health) negative at local scales. Therefore, suggested covering more (e.g., chondrichthyan low-level consumers, small fishes) areas high-latitude areas) required obtain a better understanding growth.

Language: Английский

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Early Life Intervention Using Probiotic Clostridium butyricum Improves Intestinal Development, Immune Response, and Gut Microbiota in Large Yellow Croaker (Larimichthys crocea) Larvae

Frontiers in Immunology, Journal Year: 2021, Volume and Issue: 12

Published: March 8, 2021

Marine fish larvae are vulnerable during the early life period. The intervention using probiotics may be a promising method to improve growth of larvae. In this study, 30-day feeding trial was conducted evaluate effects probiotic Clostridium butyricum (CB) on performance, intestinal development, immune response and gut microbiota large yellow croaker ( Larimichthys crocea ) Four isonitrogenous isolipidic diets were formulated with supplementation four different levels CB (5 × 10 9 CFU g −1 ), 0.00% (Control), 0.10% (CB1), 0.20% (CB2), 0.40% (CB3). Results showed that fed had significant higher final length than control group. Meanwhile, diet weight specific rate (SGR) However, no difference in survival observed among dietary treatments. significantly increased height villus enterocyte. Similarly, expression tight zonula occludens-2 zo-2 ornithine decarboxylase odc Larvae lipase leucine-aminopeptidase (LAP) activity Moreover, improved enzyme activities Sequencing bacterial 16S rRNA V4-5 region indicated altered profile decreased microbial diversities could effectively increase abundance CB, decrease some potential pathogenic bacteria larval gut. These results revealed 0.10–0.20% promote probably through promoting improving modulating microbiota.

Language: Английский

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Parasitic Copepods as Biochemical Tracers of Foraging Patterns and Dietary Shifts in Whale Sharks (Rhincodon typus Smith, 1828)

Fishes, Journal Year: 2023, Volume and Issue: 8(5), P. 261 - 261

Published: May 14, 2023

Understanding the diet of whale sharks (Rhincodon typus) is essential for development appropriate conservation strategies species. This study evaluated use parasitic copepod (Pandarus rhincodonicus) as a proxy to infer short-term foraging habitats and trophic positions shark hosts. To accomplish this, bulk stable carbon (δ13C) nitrogen (δ15N) isotope compositions were analysed from 72 paired samples skin (dermal) tissues copepods collected across six years at Ningaloo Reef aggregation site, Western Australia. found that δ15N parasites hosts strongly correlated. As turn-over times parasite differ (months vs. years, respectively), ability predict values indicates remain consistent these timeframes. Contrastingly, δ13C in host weakly correlated, likely reflecting differences physiology lifecycle compared host. Our results suggest provides reliable position their hosts, but interpretation will require future studies on P. rhincodonicus.

Language: Английский

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Ontogenetic shift or not? Different foraging trade‐offs within the meso‐ to bathypelagic fish community

Ecology and Evolution, Journal Year: 2024, Volume and Issue: 14(3)

Published: March 1, 2024

During ontogeny, the increase in body size forces species to make trade-offs between their food requirements, conditions necessary for growth and reproduction as well avoidance of predators. Ontogenetic changes are leading seek out habitats resources that meet needs. To this end, ontogenetic nocturnal habitat (vertical use water column) type (based on stable isotopes nitrogen) were investigated 12 deep pelagic fish from Bay Biscay Northeast Atlantic. Our results revealed existence major differences strategies employed by fishes. Some showed both vertical (e.g. Jewel lanternfish (

Language: Английский

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The relationship between trophic level and body size in fishes depends on functional traits

Ecological Monographs, Journal Year: 2020, Volume and Issue: 90(4)

Published: May 2, 2020

Abstract Predators typically are larger than their prey, and consequently, trophic level should increase with body size. Whereas this relationship has helped in developing predictions about food web structure dynamics mesocosms simple communities, a trophic‐level–body‐size may not exist for all kinds of communities or taxa, especially those many non‐carnivorous species. Moreover, functional traits associated generally have been considered. Herein, we examine the correlation between size fishes how vary relation to (body dimensions, mouth orientation, tooth shape, gill rakers, gut length) guilds (carnivorous vs. non‐carnivorous). We analyzed data from morphological measurements dietary analyses performed on thousands specimens freshwater estuarine habitats across three zoogeographic regions (Neartic, Neotropical, Afrotropical). A positive was only found carnivorous fishes. No when species were together, rejecting idea that is positively related generally. This result consistent even using either mass standard length as measure size, (average values) individual response variable. At intraspecific level, varied consistently one third species, among which 40% had relationships. Body depth, width relationship. Overall, predators conical triangular serrated teeth, large mouths, elongated/and/or fusiform bodies tend relationships, whereas primarily unicuspid multicuspid deep small medium sized gapes tended negative Given diverse ecological strategies encompassed by fishes, patterns processes be inferred based solely Research integrates multiple ecology will improve understanding dynamics.

Language: Английский

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Feeding behavior and species interactions increase the bioavailability of microplastics to benthic food webs

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 896, P. 165261 - 165261

Published: July 1, 2023

Language: Английский

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Uncertainty about predation risk: a conceptual review

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2023, Volume and Issue: 99(1), P. 238 - 252

Published: Oct. 15, 2023

ABSTRACT Uncertainty has long been of interest to economists and psychologists more recently gained attention among ecologists. In the ecological world, animals must regularly make decisions related finding resources avoiding threats. Here, we describe uncertainty as a perceptual phenomenon decision‐makers, focus specifically on functional ecology such regarding predation risk. Like all uncertainty, about risk reflects informational limitations. When cues are available, they may be novel (i.e. unknown information), incomplete, unreliable, overly abundant complex, or conflicting. We review recent studies that have used these limitations induce These typically either over‐responses novelty neophobia) memory attenuation proxies for measuring uncertainty. Because changes in environment, particularly unpredictable changes, drive limitations, assessing variance spatio‐temporal risk, intensity predator encounter rate, diversity. also highlight anthropogenic within habitats likely dramatic impacts information availability thus antipredator modern world.

Language: Английский

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Tackling the jelly web: Trophic ecology of gelatinous zooplankton in oceanic food webs of the eastern tropical Atlantic assessed by stable isotope analysis

Limnology and Oceanography, Journal Year: 2020, Volume and Issue: 66(2), P. 289 - 305

Published: Sept. 22, 2020

Abstract Gelatinous zooplankton can be present in high biomass and taxonomic diversity planktonic oceanic food webs, yet the trophic structuring importance of this “jelly web” remain incompletely understood. To address knowledge gap, we provide a holistic characterization jelly web eastern tropical Atlantic, based on δ 13 C 15 N stable isotope analysis unique gelatinous sample set. The covered most isotopic niche space entire web, spanning > 3 levels, ranging from herbivores (e.g., pyrosomes) to higher predators ctenophores), highlighting diverse functional roles broad possible relevance zooplankton. Among taxa, comparisons niches pointed presence differentiation resource partitioning, but also highlighted potential for competition, e.g., between hydromedusae siphonophores. Significant differences spatial (seamount vs. open ocean) depth‐resolved patterns (0–400 m 400–1000 m) additional complexity, raise questions about extent connectivity locations differential vertical coupling groups. Added complexity resulted inconsistent ontogenetic shifts among We conclude that by within substantial at spatial, depth, taxon level call more careful consideration models. In light climate change fishing pressure, data presented here valuable baseline against which measure future observations communities Atlantic.

Language: Английский

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