Dataset Information

Prey diversity as a driver of resource partitioning between river-dwelling fish species.

ABSTRACT: Although food resource partitioning among sympatric species has often been explored in riverine systems, the potential influence of prey diversity on resource partitioning is little known. Using empirical data, we modeled food resource partitioning (assessed as dietary overlap) of coexisting juvenile Atlantic salmon (Salmo salar) and alpine bullhead (Cottus poecilopus). Explanatory variables incorporated into the model were fish abundance, benthic prey diversity and abundance, and several dietary metrics to give a total of seventeen potential explanatory variables. First, a forward stepwise procedure based on the Akaike information criterion was used to select explanatory variables with significant effects on food resource partitioning. Then, linear mixed-effect models were constructed using the selected explanatory variables and with sampling site as a random factor. Food resource partitioning between salmon and bullhead increased significantly with increasing prey diversity, and the variation in food resource partitioning was best described by the model that included prey diversity as the only explanatory variable. This study provides empirical support for the notion that prey diversity is a key driver of resource partitioning among competing species.

SUBMITTER: Sanchez-Hernandez J

PROVIDER: S-EPMC5383502 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Prey diversity as a driver of resource partitioning between river-dwelling fish species.

Sánchez-Hernández Javier J Gabler Heidi-Marie HM Amundsen Per-Arne PA

Ecology and evolution 20170226 7

Although food resource partitioning among sympatric species has often been explored in riverine systems, the potential influence of prey diversity on resource partitioning is little known. Using empirical data, we modeled food resource partitioning (assessed as dietary overlap) of coexisting juvenile Atlantic salmon (<i>Salmo salar</i>) and alpine bullhead (<i>Cottus poecilopus</i>). Explanatory variables incorporated into the model were fish abundance, benthic prey diversity and abundance, and ...[more]

PMID: 28405272

Similar Datasets

Project description:BackgroundThe link between biodiversity and ecosystem processes has firmly been established, but the mechanisms underpinning this relationship are poorly documented. Most studies have focused on terrestrial plant systems where resource use can be difficult to quantify as species rely on a limited number of common resources. Investigating resource use at the bulk level may not always be of sufficient resolution to detect subtle differences in resource use, as species-specific nutritional niches at the biochemical level may also moderate diversity effects on resource use.Methodology/principal findingsHere we use three co-occurring marine benthic echinoderms (Brissopsis lyrifera, Mesothuria intestinalis, Parastichopus tremulus) that feed on the same phytodetrital food source, to determine whether resource partitioning is the principal mechanism underpinning diversity effects on resource use. Specifically we investigate the use of phytodetrital pigments (chlorophylls and carotenoids) because many of these are essential for biological functions, including reproduction. Pigments were identified and quantified using reverse-phase high performance liquid Chromatography (HPLC) and data were analysed using a combination of extended linear regression with generalised least squares (GLS) estimation and standard multivariate techniques. Our analyses reveal no species-specific selectivity for particular algal pigments, confirming that these three species do not partition food resources at the biochemical level. Nevertheless, we demonstrate increased total resource use in diverse treatments as a result of selection effects and the dominance of one species (B. lyrifera).ConclusionOverall, we found no evidence for resource partitioning at the biochemical level, as pigment composition was similar between individuals, which is likely due to plentiful food availability. Reduced intra-specific competition in the species mixture combined with greater adsorption efficiency and differences in feeding behaviour likely explain the dominant use of resources by B. lyrifera.

Project description:Due to the heterogeneous distribution of resources along large rivers, understanding prey utilization by basin-scale fish assemblages remains a challenge, and thus, recognizing regional fish trophic guilds and indicator species is important. We analyzed the stomach contents of 96 fish species along the subtropical East River in China and identified 8 prey items (29 subcategories). Site-specific differences in fish diet composition (DC) revealed longitudinal shifts in utilized prey taxa, from upstream lotic to downstream semi-lentic items, and these were characterized by a decrease in the proportions of epilithic diatoms and aquatic insect larvae (Ephemeroptera and Chironomidae) accompanied by an increase in bivalves (Corbicula and Limnoperna), shrimps and fishes, and organic sediments. The relative prey consumption weighted by fish abundance and biomass indicated that decreasing insect consumption and increasing detritus consumption were two fundamental vectors governing fish-centered feeding pathways. Seventeen prey-oriented fish guilds that were clustered based on DC matrix determined the spatial variation in the fish trophic structure. The cumulative presence of (a) upstream guilds reliant on insects and epiphytes, (b) midstream guilds reliant on hydrophytes, molluscs, and nekton, and (c) downstream guilds reliant on detritus, annelids, and plankton resulted in a longitudinal increase in guild richness, but this continuity was interrupted near the industrialized estuary. The most abundant 28 fish species across the guilds were selected as trophic indicator species; their spatial distribution significantly (p < 0.05) explained >80% of the environmental and prey variables identified. These species signified the availability of predator-prey links in distinct habitats and the key environmental factors supporting these links. With a high contribution (>51%) of exotic species, an increase in detritivores downstream distinguishes the subtropical East River from temperate rivers. Particularly, in the disturbed lower reaches, the dominance of detritivores prevailed over the predicted increase in other feeding groups (e.g., omnivores and carnivores).

Project description:The Merbok River (north-west of Peninsular Malaysia) is a mangrove estuary that provides habitat for over 100 species of fish, which are economically and ecologically important. Threats such as habitat loss and overfishing are becoming a great concern for fisheries conservation and management. The identification of larval fish in this estuarine system is important to complement information on the adults. This is because the data could inform the spawning behaviour, reproductive biology, selection of nursery grounds and migration route of fish. Such information is invaluable for fisheries and aquatic environmental monitoring, and thus for their conservation and management. However, identifying fish larvae is a challenging task based only on morphology and even traditional DNA barcoding. To address this, DNA metabarcoding was utilised to detect the diversity of fish in the Merbok River. To complete the study, the fish larvae were collected at six sampling sites of the river. The extracted larval DNA was amplified for the Cytochrome Oxidase subunit 1 (COI) and 12S ribosomal RNA (12S rRNA) genes based on the metabarcoding approach using shotgun sequencing on the next-generation sequencing (NGS) Illumina MiSeq platform. Eighty-nine species from 65 genera and 41 families were detected, with Oryzias javanicus, Oryzias dancena, Lutjanus argentimaculatus and Lutjanus malabaricus among the most common species. The lower diversity observed from previous morphological studies is suggested to be mainly due to seasonal variation over the sampling period between the two methods and limited 12S rRNA sequences in current databases. The metabarcode data and a validation Sanger sequencing step using 15 species-specific primer pairs detected three species in common: Oryzias javanicus, Decapterus maruadsi and Pennahia macrocephalus. Several discrepancies observed between the two molecular approaches could be attributed to contaminants during sampling and DNA extraction, which could mask the presence of target species, especially when DNA from the contaminants is more abundant than the target organisms. In conclusion, this rapid and cost-effective identification method using DNA metabarcoding allowed the detection of numerous fish species from bulk larval samples in the Merbok River. This method can be applied to other sites and other organisms of interest.

Dataset Information

Prey diversity as a driver of resource partitioning between river-dwelling fish species.

Publications

Prey diversity as a driver of resource partitioning between river-dwelling fish species.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure