Fish on the roof of the world: densities, habitats and trophic position of stone loaches (Triplophysa) in Tibetan streams

2017 ◽  
Vol 68 (1) ◽  
pp. 53 ◽  
Author(s):  
Dean Jacobsen ◽  
Søren Kock Laursen ◽  
Ladislav Hamerlik ◽  
Karen Moltesen ◽  
Anders Michelsen ◽  
...  
Keyword(s):  
Trophic Position ◽  
Stomach Contents ◽  
Benthic Algae ◽  
Stomach Content Analysis ◽  
Food Sources ◽  
Fish Length ◽  
The Tibetan Plateau ◽  
Running Waters ◽  
Ecological Data ◽  
Percentage Cover

The fast increase in temperature on the Tibetan Plateau, with anticipated future changes in aquatic ecosystems and biodiversity, highlights the urgent need for ecological data on the sparsely studied Tibetan running waters. In the present study we surveyed eight Tibetan streams to obtain data on densities, feeding selectivity and trophic position of the stone loach Triplophysa. Benthic algae, detritus, macroinvertebrates and fish were quantified and collected for stable isotope and stomach content analysis. Triplophysa density (mean 0.70 individuals m–2, maximum 1.6 individuals m–2) decreased with altitude and increased with the percentage cover of fine substratum. Glacier-fed sites tended to have the lowest fish densities, whereas the highest densities were found near lakes. Mean fish length (4.1–9.6cm) was positively related to the percentage cover of coarse substratum. Triplophysa was omnivorous, but the composition of the stomach contents varied greatly between sites and among individuals. Algal matter was ingested at most sites, but macroinvertebrates (Chironomidae, Baetidae and Simuliidae) dominated the ingestion (average 50–100%). The trophic position of Triplophysa, identified from δ15N (‰) of the biota, varied between 2.6 and 4.2 among localities (mean 3.6) and was inversely related to the biomass of benthic algae, but unrelated to quantities of other potential food sources.

Depth-specific patterns in benthic–planktonic food web relationships in Lake Superior

2006 ◽  
Vol 63 (7) ◽  
pp. 1496-1503 ◽  
Author(s):  
Michael E Sierszen ◽  
Gregory S Peterson ◽  
Jill V Scharold
Keyword(s):  
Great Lakes ◽  
Food Web ◽  
Food Webs ◽  
Water Column ◽  
Trophic Position ◽  
Lake Superior ◽  
Benthic Algae ◽  
Isotope Ratios ◽  
Food Sources ◽  
Large Lakes

In an investigation of the spatial characteristics of Laurentian Great Lakes food webs, we examined the trophic relationship between benthic amphipods (Diporeia) and plankton in Lake Superior. We analyzed the carbon and nitrogen stable isotope ratios of Diporeia and plankton at stations in water column depths of 4–300 m. Neither δ15N nor δ13C of plankton from the upper 50 m of the water column varied significantly with station depth. Diporeia isotope ratios exhibited depth-specific patterns reflecting changes in food sources and food web relationships with plankton. Diporeia was 13C enriched at station depths of <40 m, reflecting increased dietary importance of benthic algae. There was a systematic increase in Diporeia δ15N with depth, which appeared to result from a combination of dietary shifts in the nearshore and decompositional changes in Diporeia's principal food, sedimented plankton, in deep habitats. Diporeia δ13C and δ15N together described changes in food web isotope baseline with depth. They also discriminated three depth strata representing photic, mid-depth, and profundal zones. These findings have implications for our understanding of Great Lakes food webs and analyses of trophic position within them, the ecology of zoobenthos and plankton communities, and sampling designs for large lakes.

scholarly journals Bioaccumulation of mercury in fishes of Jagadishpur Reservoir, Nepal

2019 ◽  
Vol 7 ◽  
pp. 17-23
Author(s):  
Prakash Acharya ◽  
Chhatra Mani Sharma ◽  
Shichang Kang ◽  
Lekhendra Tripathee ◽  
Junming Guo ◽  
...  
Keyword(s):  
Fish Species ◽  
Fish Community ◽  
Food Resource ◽  
Stomach Contents ◽  
Stomach Content Analysis ◽  
Trophic Levels ◽  
Fish Length ◽  
Mystus Vittatus ◽  
Total Hg ◽  
Food Resource Utilization

Stable isotope ratios of nitrogen (δ15N, ‰) and carbon (δ13C, ‰), accompanied by stomach contents were used to assess the food chain and trophic transfer of mercury in fifty-three marketable sized fish belonging to five species (Channa punctatus, Mystus vittatus, Nandus nandus, Puntius sophore and Xenentodon cancila) from the Jagadishpur Reservoir, Nepal. The highest total Hg concentration was found in X. cancila with an average of 800.42(±279.36) µg/kg exceeding the international marketing limit (500 mg/kg), a carnivorous species. However, except for some individuals of N. nandus, total Hg concentrations in other fish species in the present study were significantly lower than that limit. The fish community had at least two trophic levels (Δ15N > 5.6), C. punctatus with the highest and M. vittatus the lowest signatures of δ15N, which was also supported by the stomach content analysis. There was neither correlation between total Hg and δ15N nor connectivity in food resource utilization (based on δ13C), indicating no biomagnification among these fish species. In addition, Hg concentrations were not significantly correlated to total fish length in any of the species. Fish species in the present study have low Hg content accompanied by low biomagnification through the studied fish community.

Spatial and seasonal variability in the diet of round goby (Neogobius melanostomus): stable isotopes indicate that stomach contents overestimate the importance of dreissenids

2012 ◽  
Vol 69 (3) ◽  
pp. 573-586 ◽  
Author(s):  
Jaclyn M. Brush ◽  
Aaron T. Fisk ◽  
Nigel E. Hussey ◽  
Timothy B. Johnson
Keyword(s):  
Stable Isotopes ◽  
Trophic Position ◽  
Round Goby ◽  
Stomach Contents ◽  
Stomach Content Analysis ◽  
Neogobius Melanostomus ◽  
Important Prey ◽  
Round Gobies ◽  
Common Items ◽  
The Impact

Our results provide new information that diet, carbon source and trophic position of an invasive fish species, round goby ( Neogobius melanostomus ), varies seasonally, spatially and with body size in littoral habitats of Lake Ontario. Based on stomach contents and stable isotopes, round goby fed at a higher trophic position in the cooler, less productive Kingston Basin relative to the Bay of Quinte. Bay of Quinte round goby were more reliant on terrestrial carbon, whereas littoral carbon dominated in the Kingston Basin. Although stomach contents suggested dreissenids were the dominant prey item of round goby, stable isotope mixing models estimated that dreissenids were never >39% and 11% of the diet in Bay of Quinte and Kingston Basin, respectively. Stable isotopes indicated amphipods, chironomids and cladocerans were the most important prey, and were at times common items in stomach contents, but this varied with site, season and year. Given their high abundance, the impact of round gobies on the benthic biodiversity of the Great Lakes may be more significant than indicated by stomach content analysis alone.

scholarly journals Corrigendum to: Carbon sources supporting Australia's most widely distributed freshwater fish, Nematalosa erebi (Günther) (Clupeidae: Dorosomatinae)

2021 ◽  
Vol 72 (2) ◽  
pp. 299
Author(s):  
Bradley J. Pusey ◽  
Timothy D. Jardine ◽  
Leah S. Beesley ◽  
Mark J. Kennard ◽  
Tsz Wai Ho ◽  
...  
Keyword(s):  
Content Analysis ◽  
Food Webs ◽  
Freshwater Fish ◽  
Stomach Content ◽  
Benthic Algae ◽  
Stomach Content Analysis ◽  
Food Sources ◽  
Small Fish ◽  
Northern Australia ◽  
Green Algal

Both brown (detrital-based) and green (algal-based) food pathways support freshwater food webs, although the importance of either source may vary within species, regions and different phases of the flow regime. The bony bream (Nematalosa erebi Clupeidae: Dorosomatinae) is one of Australia's most widely distributed freshwater fish species and is a key component of freshwater food webs, especially in northern Australia. We sought to better define the feeding habits of this species, previously classified as a detritivore, algivore or zooplanktivore (or combinations thereof), by undertaking meta-analyses of published accounts based on stomach content analysis and 13C and 15N stable isotope analysis. Stomach content analysis clearly indicated that detritus was the dominant food item, although benthic algae could be an important dietary component in some habitats (inland river flood plains) and during the wet season. Zooplankton were important for small fish (i.e. juveniles 13C enriched, indicating the latter source was not the dominant contributor to the biomass of this species. However, using site-specific data and a regression approach, a significant relationship was revealed between algal carbon and that of large fish, suggesting that carbon derived from benthic algae contributed ~20% of the carbon of adult bony bream. Zooplankton contributed a similar amount. Zooplankton provided the majority of carbon for small fish. We contend that detritus derived from terrestrial vegetation is the likely remaining carbon source for large bony bream, and this interpretation was supported by the outcomes of multiple regression analyses. Although previous studies of aquatic food webs in northern Australia have emphasised the importance of high-quality algal basal resources, this study indicates that terrestrial sources may be important for some species and demonstrates the need to better consider the circumstances that cause biota to switch between different food sources.

Food sources of common dolphinfish (Coryphaena hippurus) based on stomach content and stable isotopes analyses

2014 ◽  
Vol 95 (3) ◽  
pp. 579-591 ◽  
Author(s):  
A. Tripp-Valdez ◽  
F. Galván-Magaña ◽  
S. Ortega-García
Keyword(s):  
Stable Isotope ◽  
Stomach Content ◽  
Gulf Of California ◽  
Stomach Contents ◽  
Isotopic Analysis ◽  
Stomach Content Analysis ◽  
Food Sources ◽  
Important Prey ◽  
Opportunistic Predator ◽  
Ecological Importance

Dolphinfish (Mahimahi) are a high-demand resource for sport and coastal fisheries, mainly in the Pacific Ocean. Due to their economic and ecological importance, studies of their biology are very important to understand their function in ecosystems. We used stable isotope and stomach content analyses to determine the most important prey of the common dolphinfish, as well as the trophic level of this species in two areas of the southern Gulf of California. Stomach contents of 445 specimens were analysed. Using both techniques, we found that the most important prey for dolphinfish in the southern Gulf of California were three invertebrate species followed by fish. This contrasts with results from other authors who found that this species was mainly piscivorous in other locations. Stomach content analysis indicated differences in prey biomass by area, season and size class. The isotopic analysis did not show significant differences between seasons or sexes. Both stomach contents and stable isotope analyses showed that although this predator consumed a wide prey spectrum, only a few prey items made up the bulk of the diet, which resulted in a low SD in δ15N values and low Levin's index values. We conclude that this fish is an opportunistic predator that may consume a wide prey spectrum, but that it mainly consumes prey that are abundant in the area, such as crustaceans and cephalopods in the Gulf of California.

scholarly journals Feeding habits and population aspects of the spotted goatfish, Pseudupeneus maculatus (Perciformes: Mullidae), on the continental shelf of northeast Brazil

2020 ◽  
Vol 84 (2) ◽  
Author(s):  
Andrey Soares ◽  
Alex Souza Lira ◽  
Júlio Guazzelli Gonzalez ◽  
Leandro Nolé Eduardo ◽  
Flávia Lucena-Frédou ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Continental Shelf ◽  
Trophic Position ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Distribution Patterns ◽  
Isotope Ratios ◽  
Stomach Content Analysis ◽  
Stable Isotope Ratios ◽  
Weight Percentage

This study provides information about the feeding habits, population aspects and spatial distribution of the spot­ted goatfish, Pseudupeneus maculatus, along the coast of the tropical Brazilian continental shelf. Distribution patterns are described using length frequencies and catch rates. Stable isotope ratios of carbon (δ13C) and nitrogen (δ15N), along with stomach contents, were analysed to determine the diet of the spotted goatfish. Multivariate analysis and numerical indicators of the diet, such as numerical frequency, frequency of occurrence and weight percentage, were computed to evaluate the diet composition. The mean trophic position was defined using both stable isotope ratios and stomach content analysis. The length at first maturity for the species was determined as 13.7 cm. A slight pattern in size distribution was observed, with mean size increasing with depth along the shelf. The diet was mainly composed of crustaceans, teleosts and Polychaeta. No clear dietary difference was found between habitat types, water depth or latitude. Both trophic positions estimated by stable isotopes and stomach contents analysis ranged between levels 3 and 4. P. Maculatus was found to be feeding on many rare and infrequent prey items, classifying it as a generalist zoobenthivorous predator, probably due to its efficient search strategy.

Trophic position scales positively with body size within but not among four species of rocky reef predators

2020 ◽  
Vol 640 ◽  
pp. 189-200 ◽  
Author(s):  
AM Olson ◽  
A Frid ◽  
JBQ dos Santos ◽  
F Juanes
Keyword(s):  
Body Size ◽  
Trophic Position ◽  
Stomach Contents ◽  
Rocky Reef ◽  
Morphometric Traits ◽  
Predator Species ◽  
Predatory Fishes ◽  
Average Size ◽  
Interspecific Comparisons ◽  
Large Predators

Intra- and interspecifically, larger-bodied predators generally occupy higher trophic positions (TPs). With widespread declines in large predators, there is a need to understand their size-based trophic roles to predict ecosystem-level responses. In British Columbia, Canada, we examined size-based trophic interactions between predatory fishes—3 rockfish species (genus Sebastes) and lingcod Ophiodon elongatus—and their prey, converting predator δ15N signatures to TP and analyzing stomach contents. Intraspecifically, TP scaled positively with predator length and gape width, but the rates of change varied by species. Interspecifically, TP did not scale positively with the observed mean sizes or known maximum sizes of species. Lingcod TP was lower than that of yelloweye and quillback rockfishes, which were 51 and 37%, respectively, smaller than lingcod. Yellowtail rockfish had the smallest average size, yet their mean TP did not differ significantly from that of lingcod. Neither species differences in some morphometric traits known to influence body size-TP relationships nor phylogenetic history explained these results. Most prey consumed were <20% of the predator’s size, which might partially explain the lack of a size-based trophic hierarchy among species. Currently, large size classes of rockfishes are being lost due to fisheries and perhaps climate-driven changes. Our findings on intraspecific size-TP relationships indicate that fishery removals of large individuals may diminish trophic structures. Interspecific comparisons of TP suggest that, along with size, species remain an important factor in understanding trophic dynamics. In addition, smaller-bodied predator species may have significant ecological roles to be considered in ecosystem-based fisheries management.

scholarly journals FEEDING HABITS AND HELMINTH PARASITES OF SARDINE (S. PILCHARDUS) AND ANCHOVY (E. ENCRASICOLUS) IN THE ADRIATIC SEA

2015 ◽  
Vol 17 (1) ◽  
pp. 216 ◽  
Author(s):  
B. ZORICA ◽  
V. ČIKES KEČ ◽  
O. VIDJAK ◽  
I. MLADINEO ◽  
D. EZGETA BALIČ
Keyword(s):  
Diet Composition ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Stomach Content Analysis ◽  
Helminth Parasites ◽  
Significant Difference ◽  
Prey Composition ◽  
One Year ◽  
Paratenic Hosts ◽  
Hysterothylacium Aduncum

We examined the stomach contents of two of the most economically and ecologically important small pelagic fish species, the sardine, Sardina pilchardus and the anchovy, Engraulis encrasicolus, obtained monthly from commercial purse-seine catches operating on Croatian fishing grounds during a one-year period (January–December, 2011). Both species generally showed a similar diet, with copepod and decapod larvae as dominant prey groups. The composition of anchovy and sardine stomach contents was not size- or sex-related, but throughout the year, a significant difference in diet composition was observed for each species as well as between species. Two gastrointerstinal helminths; the digenean Parahemiurus merus and nematode Hysterothylacium aduncum, were recorded during the stomach content analysis. Differences in population dynamics between the two parasites are congruent with differences in the prey composition of sardine and anchovy, reflecting fine-tuned interactions in the trophic web between parasites and intermediate or paratenic hosts included in the sardine and anchovy diet.

Determination of food sources and trophic position in Malaysian tropical highland streams using carbon and nitrogen stable isotopes

2017 ◽  
Vol 37 (2) ◽  
pp. 97-104 ◽  
Author(s):  
Dhiya Shafiqah Ridzuan ◽  
Che Salmah Md. Rawi ◽  
Suhaila Abdul Hamid ◽  
Salman Abdo Al-Shami
Keyword(s):  
Stable Isotopes ◽  
Trophic Position ◽  
Food Sources ◽  
Nitrogen Stable Isotopes ◽  
Carbon And Nitrogen ◽  
Highland Streams

scholarly journals Food Habits and Diet Relationship in the Redbelly Tilapia (Tilapia zillii) and Guenther’s Mouthbrooder (Chromidotilapia guntheri) from an Abandoned Gold Mine Reservoir, Southwestern Nigeria

2018 ◽  
Vol 10 (2) ◽  
pp. 148-155
Author(s):  
Olusola Olaniyi KOMOLAFE ◽  
Timothy Olalekan AMOO ◽  
Michael Olufemi AWODIRAN
Keyword(s):  
Feeding Habits ◽  
Stomach Contents ◽  
Food Sources ◽  
Gold Mine ◽  
Southwestern Nigeria ◽  
Food Items ◽  
Tilapia Zillii ◽  
Gill Net ◽  
Food And Feeding ◽  
Index Value

The food and feeding habits of the redbelly Tilapia (Tilapia zillii) and Guenther’s mouthbrooder (Chromidotilapia guntheri) were investigated in an abandoned gold mine reservoir at Igun from June 2013 to May 2014. Using a cast net and gill-net fishing gears, 370 fish individuals were caught and their stomach contents were analysed by using the frequency of occurrence and numerical methods. Tilapia zillii comprised 53.78% (199 individuals), while Chromidotilapia guntheri covered up the remaining percentage (46.22%) which is made up of 171 individuals. Food items in the stomachs of T. zillii individuals predominantly consisted of detritus, mud and algae (77.97%), while those in C. guntheri individuals mostly consisted fish remains, detritus and algae (81.67%). T. zillii exploited more food items (23 of 27) as compared to C. guntheri (17 of 27). The Schoener’s index value for the species was 0.65. The study showed that T. zillii and C. guntheri exhibited benthopelagic exploitation and are mainly herbivorous and omnivorous respectively based on the food items observed in the stomach contents of these species. The fish species fed on related food items as confirmed by Schoener’s overlap index (0.65), suggesting that there was overlap in the dietary requirements of the two species. This index value, however, was probably not an indication of competition for food between these two species because they exploited abundant food sources.

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