Role of body size and habitat complexity in the diet of the invasive Micropterus salmoides (Lacépède): optimal foraging theory matters

Biological Invasions, Год журнала: 2025, Номер 27(1)

Опубликована: Янв. 1, 2025

Язык: 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, Год журнала: 2020, Номер 66(2), С. 289 - 305

Опубликована: Сен. 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.

Язык: Английский

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Life‐history genomic regions explain differences in Atlantic salmon marine diet specialization

Journal of Animal Ecology, Год журнала: 2020, Номер 89(11), С. 2677 - 2691

Опубликована: Авг. 17, 2020

Abstract Animals employ various foraging strategies along their ontogeny to acquire energy, and with varying degree of efficiencies, support growth, maturation subsequent reproduction events. Individuals that can efficiently energy early are more likely mature at an earlier age, as a result faster gain which fuel reproduction. We aimed test the hypothesis heritable resource acquisition variation covaries efficiency would influence timing individuals. To this hypothesis, we utilized Atlantic salmon model exhibits simple, hence trackable, genetic control age. then monitored in diet (quantified stomach fullness composition) individuals different ages, linked it genomic regions (haploblocks) were previously identified be associated age‐at‐maturity. Consistent demonstrated one life‐history tested (s ix6 ) was indeed age‐dependent differences fullness. Prey composition marginally six6 , suggestively (but non‐significantly) vgll3 regions. further showed switched so‐called ‘feast famine’ strategy ontogeny, where older age groups exhibited heavier content, but came expense running on empty often. These results suggest underlying utilization may explain basis structure salmon. Given ontogenetic has component strong spatial diversity these regions, predict populations diverse will have evolutionary responses future changes marine food web structures.

Язык: Английский

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Fresh perspectives on the River Continuum Concept require trophic ecology approaches focussed on food web structure and energy mobilisation routes

Journal of Animal Ecology, Год журнала: 2023, Номер 92(5), С. 957 - 964

Опубликована: Апрель 7, 2023

Abstract Stream‐dwelling communities are expected to show a gradual replacement of the dominant feeding types following type resources found along river continuum. Yet, underlying longitudinal gradients in food web structure and energy flow‐paths remain poorly understood. Here, I synthesise novel research on River Continuum Concept (RCC) identify promising areas for future linked changes food‐chain length mobilisation routes. For example, links connectance should reach maximum values mid‐order rivers then decrease mouths uncovered diversity patterns. Regarding routes, fuelling between allochthonous (leaf litter) autochthonous (periphyton) be expected. Beyond primary basal resource consumer paths, other (e.g. riparian arthropod inputs) fish prey) inputs subsidising higher level consumers may changes, that is, terrestrial invertebrates decreasing but piscivory increasing downstream. However, role these inputs, can alter predator niche variation have indirect community‐based effects, both continuum is not clear yet. Incorporating into RCC principles necessary broad understanding ecosystem functioning trophic riverine systems, driving emergence insights. How function webs adapt physical biological environments represent challenge next generation stream ecologists.

Язык: Английский

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The effect of inter‐ and intraspecific competition on individual and population niche widths: a four‐decade study on two interacting salmonids

Oikos, Год журнала: 2021, Номер 130(10), С. 1679 - 1691

Опубликована: Июль 12, 2021

Competition is assumed to shape niche widths, affecting species survival and coexistence. Expectedly, high interspecific competition will reduce population whereas intraspecific do the opposite. Here we test in situ how intra‐ affects trophic resource use individual widths of two lacustrine fish species, Arctic charr brown trout, covering a 40 year study period with highly contrasting competitive impacts prior following large‐scale culling experiment. Initially, an overcrowded dominated system, trout being nearly absent. The experiment reduced littoral density by 80%, whereupon gradually increased its system. Thus, over period, went from low competition, followed increasing trout. As hypothesized, relaxed experimental diet specialization compressed width charr. During initial increase population, there was large dietary overlap between species. Over subsequent intensified build‐up their chiefly declined due shift towards enhanced zooplankton consumption. Contrary theoretical expectations, competition. In contrast, remained stable time, confirming superiority. associated long‐term research revealed pronounced temporal dynamics inferior competitor, substantiating that have on niches.

Язык: Английский

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Diet composition of redfish (Sebastes sp.) during periods of population collapse and massive resurgence in the Gulf of St. Lawrence

Frontiers in Marine Science, Год журнала: 2022, Номер 9

Опубликована: Авг. 5, 2022

Redfish ( Sebastes mentella and S. fasciatus ) are back at spectacular record high levels in the Gulf of St. Lawrence (GSL) effects this massive resurgence on other components food web remain largely unknown. To better understand trophic implications surging redfish biomass within GSL ecosystem, 3,690 stomachs containing were collected during two periods: one characterised by low abundance (1993–1999) a period (2015–2019). Taxonomical analysis stomach contents from individuals different sizes three subareas was carried out to determine diet composition both periods. Zooplankton represented main prey category for small (< 20 cm), which driven predation amphipods, mostly Themisto sp. North-East Gulf, 1990s copepods genus Calanus deep channels euphausiids North-West 2010s. still dominated medium (20–30 cm) while predominant Shrimp consumption increased with size species particularly important large (≥ 30 pink glass shrimp Pasiphaea multidentata ), Laurentian Channel northern Pandalus borealis especially Gulf. represents major concern dynamics supports valuable fishery but has been declining since several years. Piscivory observed diet, capelin Mallotus villosus being fish (cannibalism) 2010s, suggesting density-dependent control density redfish. By presenting detailed overview into its temporal variability, present study offers first look possible future impacts resurging groundfish ecosystem.

Язык: Английский

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Multi-omics analysis revealed the differences in lipid metabolism of the gut between adult and juvenile yellowfin tuna (Thunnus albacares)

Frontiers in Microbiology, Год журнала: 2024, Номер 14

Опубликована: Янв. 11, 2024

Tuna has a cost-effective energy supply to support the regional endothermic and high-speed swimming performance. The gut symbiotic microbiotas their metabolites play essential roles in tuna's diet digestion, absorption, acquirement, which are often highly related ontogenetic development of tuna. We compared microbial compositions metabolites, as well mRNA expression intestine between juvenile adult yellowfin tuna using 16S rRNA sequencing, metabolomic transcriptomic, respectively. results revealed that adults had significantly higher diversity abundance Acinetobacter than juveniles. Regarding microbiota-derived fatty acids, especially glycerophospholipid sphingolipid, were enriched Moreover, short-chain acid (butyrate isobutyrate) contents To find relationship host physiology, intestinal transcriptome analysis demonstrated pathways differential genes (DEGs) lipid metabolism pathway, including "fat digestion absorption," "cholesterol metabolism," "steroid hormone biosynthesis," "glycerolipid "glycerophospholipid metabolism." However, protein absorption pancreatic secretion conjoint indicated both (DMs) DEGs remarkably regulation glycerophospholipids tunas. This study highlights role fish nutrition metabolism. These findings provide new insights into view shifts on health function marine species.

Язык: Английский

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Body condition metrics explain fish movement in experimental streams

Journal of Zoology, Год журнала: 2023, Номер 320(1), С. 18 - 28

Опубликована: Янв. 22, 2023

Abstract Body condition refers to an array of physiological or nutritious states in animals, but body is typically measured using a single metric animal behavior studies. In this paper, we conducted three‐day laboratory study evaluate whether metrics affected movement wild‐caught creek chub ( Semotilus atromaculatus ) at 16 and 22°C. Movement was counted between two circular tanks connected by straight corridor, which equipped with pair passive integrated transponder antennas. Fish most frequent during periods darkness simulated photoperiod, more mobile individuals consistently moved frequently across the 3 days. general, better were than those poorer condition, different degrees. Specifically, per cent weight loss dry matter content (ratio wet versus dehydrated weight) predictors weight‐at‐length, used as surrogate animals. addition, length interacted affect fish movement, where smaller significantly that larger individuals. effects on activity similar This demonstrates may not always certain way. need be carefully selected when context behavior, should tested feasible.

Язык: Английский

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Feeding ecology of redfish (Sebastes sp.) inferred from the integrated use of fatty acid profiles as complementary dietary tracers to stomach content analysis

Journal of Fish Biology, Год журнала: 2023, Номер 102(5), С. 1049 - 1066

Опубликована: Фев. 16, 2023

In the northern Gulf of St. Lawrence (nGSL), redfish (Sebastes mentella and Sebastes fasciatus combined) are at record levels abundance following strong recruitment three consecutive cohorts in 2011-2013 have become by far most abundant demersal fish region. Understanding trophic relationships is essential for effective management conservation species nGSL ecosystem. To date, description quantification diet region been restricted to conventional stomach content analysis (SCA). Using fatty acid (FA) profiles as complementary dietary tracers, authors conducted multivariate analyses on 350 livers which were collected combination with contents during a bottom-trawl scientific survey August 2017. The predator FA compared those eight different prey types identified important SCA. Results suggested similitude between SCA results, zooplankton being more related small (<20 cm) medium (20-30 (16:1n7, 20:1n?, 22:1n9 20:5n3) than large (≥30 ones, whereas shrimp seemed size classes (18:2n6 22:6n3) relative ones. Although offers glimpse only based recently consumed prey, provides mid-term view indicating pelagic consumption calanoid copepod confirming high predation pressure shrimp. This study constitutes first attempt combining assess redfish, highlights benefits qualitative tool suggests improvements future studies.

Язык: Английский

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

Science Advances, Год журнала: 2023, Номер 9(49)

Опубликована: Дек. 8, 2023

Tyrannosaurids were large carnivorous dinosaurs that underwent major changes in skull robusticity and body proportions as they grew, suggesting 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 Gorgosaurus libratus preserves articulated hindlimbs two yearling caenagnathid inside its abdominal cavity. The prey selectively dismembered consumed separate feeding events. This predator-prey association provides direct evidence an ontogenetic dietary shift tyrannosaurids. Juvenile individuals may have hunted small young until reached size when, to satisfy energy requirements, transitioned megaherbivores. both mesopredator apex predator roles span, factor been key evolutionary success.

Язык: Английский

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