Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation among generalist fishes is facilitated by the presence of macrophytes, which provides niches and predation shelter for fish and their prey items. Based on results from stable nitrogen (δ15N) and carbon (δ13C) isotopic mixing models, perch (Perca fluviatilis L.) and rudd (Scardinius erythrophthalmus (L.)) showed larger individual variation (i.e., variance) in trophic position in Milada as compared to Most, whereas no significant between-lake differences were observed for roach (Rutilus rutilus (L.)). Contrary to our hypothesis, all the three species showed significantly lower individual variation in the relative reliance on littoral food resources in Milada than in Most. Rudd relied significantly more whereas perch and roach relied less on littoral food resources in Milada than in Most, likely due to prevalent herbivory by rudd and prevalent zooplanktivory by perch and roach in the macrophyte-rich Milada as compared to macrophyte-poor Most. Our study demonstrates how the succession of macrophyte vegetation, via its effects on the physical and biological complexity of the littoral zone and on the availability of small prey fish and zooplankton, can strongly influence individual niche variation among generalist fishes with different ontogenetic trajectories, and hence the overall food-web structures in lake ecosystems.

Biology Centre of the Czech Academy of Sciences Institute of Hydrobiology Na Sádkách 7 České Budějovice Czech Republic

Faculty of Science University of South Bohemia in České Budějovice Branišovská 31 České Budějovice Czech Republic

Norwegian Institute for Nature Research Sluppen Trondheim Norway

University of Jyväskylä Department of Biological and Environmental Science Jyväskylä Finland

Zobrazit více v PubMed

Pimm SL, Lawton JH. On feeding on more than one trophic level. Nature 1978; 275: 542–544.

Polis GA, Anderson WB, Holt RD. Toward an integration of landscape and food web ecology: the dynamics of spatially subsidized food webs. Annu Rev Ecol Syst 1997; 28: 289–316.

Schindler DE, Scheuerell MD. Habitat coupling in lake ecosystems. Oikos 2002; 98: 177–189.

Kratina P, LeCraw RM, Ingram T, Arnholt BR. Stability and persistence of food webs with omnivory: is there a general pattern? Ecosphere 2012; 3: 1–18.

Bolnick DI, Svanbäck R, Fordyce JA, Yang LH, Davis JM, Hulsey CD, et al. The ecology of individuals: incidence and implications of individual specialization. Am Nat 2003; 161: 1–28. doi: 10.1086/343878 PubMed DOI

Araújo MS, Bolnick DI, Layman CA. The ecological causes of individual specialization. Ecol Lett 2011; 14: 948–958. doi: 10.1111/j.1461-0248.2011.01662.x PubMed DOI

Bolnick DI, Amarasekare P, Araújo MS, Bürger R, Levine JM, Novak M, et al. Why intraspecific trait variation matters in community ecology? Trends Ecol Evol 2011; 26: 183–192. doi: 10.1016/j.tree.2011.01.009 PubMed DOI PMC

Mittelbach GG, Ballew NG, Kjelvik MK. Fish behavioural types and their ecological consequences. Can J Fish Aquat Sci 2014; 71: 1–18.

Schluter D. The ecology and origin of species. Trends Ecol Evol 2001; 16: 372–380. PubMed

Svanbäck R, Persson L. Individual specialization, niche width and population dynamics: implications for trophic polymorphisms. J Anim Ecol 2004; 73: 973–982.

Losos JB. Adaptive radiation, ecological opportunity, and evolutionary determinism. Am Nat 2010; 175: 623–639. doi: 10.1086/652433 PubMed DOI

Schriver P, Bøgestrand J, Jeppesen E, Søndergaard M. Impact of submerged macrophytes on fish-zooplankton-phytoplankton interactions: large-scale enclosure experiments in a shallow eutrophic lake. Freshw Biol 1995; 33: 255–270.

Jeppesen E, Søndergaard M, Søndergaard M, Christoffersen K. The structuring role of submerged macrophytes in lakes. New York: Springer, 1992.

Newman RM. Herbivory and detritivory on freshwater macrophytes by invertebrates: a review. J N Am Benthol Soc 1991; 10: 89–114.

Warfe DM, Barmuta LA. Habitat structural complexity mediates food web dynamics in a freshwater macrophyte community. Oecologia 2006; 150: 141–154. doi: 10.1007/s00442-006-0505-1 PubMed DOI

Specziár A, Rezsu ET. Feeding guilds and food resource partitioning in a lake fish assemblage: an ontogenetic approach. J Fish Biol 2009; 75: 247–267. doi: 10.1111/j.1095-8649.2009.02283.x PubMed DOI

Kottelat M, Freyhof J. Handbook of European freshwater fishes. Berlin: Publications Kottelat, Cornol and Freyhof, 2007.

Persson L. Behavioral response to predators reverses the outcome of competition between prey species. Behav Ecol Sociobiol 1991; 28: 101–105.

Kubečka J. Succession of fish communities of Central and East European reservoirs In: Comparative Reservoir Limnology and Water Quality Management (Eds. Straškraba M., Tundisi JS. & Duncan A.). Dordecht: Kluwer Academic Publishers, 1993; pp. 153–168.

Blabolil P, Logez M, Ricard D, Prchalová M, Říha M, Sagouis A, et al. An assessment of the ecological potential of Central and Western European reservoirs based on fish communities. Fish Res 2016; 173: 80–87.

Persson L. Asymmetries in competitive and predatory interactions in fish populations–In: Size-structured populations Ecology and Evolution (Eds. Ebenman B. & Persson L.), Heidelberg: Springer-Verlag, 1988; pp. 203–218.

Craig FG. Percid Fishes–Systematics, Ecology and Exploitation. Oxford: Blackwell Science, 2000.

Lodge DM. Herbivory on freshwater macrophytes. Aquat Bot 1990; 41: 195–224.

Kapuscinski KL, Farrell JM, Wilkinson MA. Feeding patterns and population structure of an invasive cyprinid, the rudd Scardinius erythrophthalmus (Cypriniformes, Cyprinidae), in Buffalo Harbor (Lake Erie) and the upper Niagara River. Hydrobiologia 2012; 693: 169–181.

Jeppesen E, Søndergaard M, Lauridsen T, Landkildehus F. Trophic structure, species richness and biodiversity in Danish lakes: Changes along a phosphorus gradient. Freshw Biol 2000; 45: 201–218.

Olin M, Rask M, Ruuhljärvi J, Kurkilahti M, Ala-Opas P, Ylönen O. Fish community structure in mesotrophic and eutrophic lakes of southern Finland: the relative abundances of percids and cyprinids along a trophic gradient. J Fish Biol 2002; 60: 593–612.

Vašek M, Kubečka J, Peterka J, Čech M, Draštík V, Hladík M, et al. Longitudinal and vertical spatial gradients in the distribution of fish within a canyon-shaped reservoir. Int Rev Hydrobiol 2004; 89: 352–362.

Vašek M, Kubečka J, Matěna J, Seďa J. Distribution and diet of 0+ fish within a canyon-shaped European reservoir in late summer. Int Rev Hydrobiol 2006; 91: 178–194.

Persson L. Competition-induced switch in young of the year perch, Perca fluviatilis: an experimental test of resource limitation. Environ Biol Fish 1987; 19: 235–239.

Persson L, Greenberg LA. Juvenile competitive bottlenecks: the perch (Perca fluviatilis)-roach (Rutilus rutilus) interaction. Ecology 1990; 71: 44–56.

Diehl S. Fish predation and benthic community structure: the role of omnivory and habitat complexity. Ecology 1992; 73: 1646–1661.

Persson L. Predator-mediated competition in prey refuges: the importance of habitat dependent prey resources. Oikos 1993; 68: 12–22.

Diehl S. Foraging efficiency of three freshwater fishes: effects of structural complexity and light. Oikos 1988; 53: 207–214.

Winfield IJ. The influence of simulated aquatic macrophytes on the zooplankton consumption rate of juvenile roach, Rutilus rutilus, rudd, Scardinius erythrophthalmus, and perch, Perca fluviatilis. J Fish Biol 1986; 29: 37–48

Persson L, Eklöv P. Prey refuges affecting interactions between piscivorous perch and juvenile perch and roach. Ecology 1995; 76: 70–81.

Vejříková I, Vejřík L, Syväranta J, Kiljunen M, Čech M, Blabolil, et al. Distribution of Herbivorous Fish Is Frozen by Low Temperature. Sci Rep 2016; 6:39600 doi: 10.1038/srep39600 PubMed DOI PMC

CEN. Water Quality–Sampling of fish with multi-mesh gillnets. EN–14757. 2015.

Post DM. Using stable isotopes to estimate trophic position: models, methods, and assumptions. Ecology 2002; 83: 703–718.

Layman CA, Araujo MS, Boucek R, Hammerschlag-Peyer CM, Harrison E, Jud ZR, et al. Applying stable isotope to examine food-web structure: an overview of analytical tools. Biol Rev 2012; 87: 545–532. doi: 10.1111/j.1469-185X.2011.00208.x PubMed DOI

Post DM, Layman CA, Arrington DA, Takimoto G, Quattrochi J, Montana CG. Getting to the fat of the matter: models, methods and assumptions for dealing with lipids in stable isotope analyses. Oecologia 2007; 152: 179–189. doi: 10.1007/s00442-006-0630-x PubMed DOI

Bearhop S, Waldron S, Votier SC, Furness RW. Factors that influence assimilation rates and fractionation of nitrogen and carbon stable isotopes in avian blood and feathers. Physiol Biochem Zool 2002; 75: 451–8. doi: 10.1086/342800 PubMed DOI

Newsome SD, Martinez del Rio C, Bearhop S, Phillips DL. A niche for isotopic ecology. Front Ecol Environ 2007; 5: 429–436.

France RL. Critical examination of stable isotope analysis as a means for tracing carbon pathways in stream ecosystems. Can J Fish Aquat Sci 1995; 52: 651–656.

Cabana G, Rasmussen JB. Comparison of aquatic food chains using nitrogen isotopes. P Natl Acad Sci USA 1996; 93: 10844–10847. PubMed PMC

R Core Team. R: a language and environment for statistical computing. R Foundation for Statistical Computing. Vienna, Austria, 2014.

Persson L, Byström P, Wahlström E. Cannibalism and competition in Eurasian perch: population dynamics of an ontogenetic omnivore. Ecology 2000; 81: 1058–1071.

Vejřík L, Matějíčková I, Jůza T, Frouzová J, Seďa J, Blabolil P, et al. Small fish use the hypoxic pelagic zone as a refuge from predators. Freshw Biol 2016; 61: 899–913.

Persson L, Diehl S, Johansson L, Andersson G, Hamrin S. Shifts in fish communities along the productivity gradient of temperate lakes–patterns and the importance of size-structured interactions. J Fish Biol 1991; 38: 281–293.

Vašek M, Jarolím O, Čech M, Kubečka J, Peterka J, Prchalová M. The use of pelagic habitat by cyprinids in a deep riverine impoundment: Římov Reservoir, Czech Republic. Folia Zool 2008; 57: 324–336.

Jarolím O, Kubečka J, Čech M, Vašek M, Peterka J, Matěna J. Sinusoidal swimming in fishes: the role of season, density of large zooplankton, fish length, time of the day, weather condition and solar radiation. Hydrobiologia 2010; 654: 253–265.

Horppila J, Nurminen L. Food niche segregation between two herbivorous cyprinid species in a turbid lake. J Fish Biol 2009; 75: 1230–1243. doi: 10.1111/j.1095-8649.2009.02359.x PubMed DOI

Estlander S, Nurminen L, Olin M, Vinni M, Immonen S, Rask M, et al. Diet shifts and food selection of perch Perca fluviatilis and roach Rutilus rutilus in humic lakes of varying water colour. J Fish Biol 2010; 77: 241–256 doi: 10.1111/j.1095-8649.2010.02682.x PubMed DOI

Prejs A, Jackowska H. Lake macrophytes as the food of roach (Rutilus rutilus L.) and rudd (Scardinius erythrophthalmus L.). I. Species composition and dominance relations in the lake and food. Ekol Pol 1978; 26: 429–438.

Persson A, Hansson LA. Diet shift in fish following competitive release. Can J Fish Aquat Sci 1998; 56: 70–78.

Hargeby A, Blom H, Blindow I, Andersson G. Increased growth and recruitment of piscivorous perch, Perca fluviatilis, during a transient phase of expanding submerged vegetation in a shallow lake. Freshw Biol 2005; 50: 2053–2062.

Grenouillet G, Pont D. Juvenile fishes in macrophyte beds: influence of food resources, habitat structure and body size. J Fish Biol 2001; 59: 939–959.

Dennison WC, Orth RJ, Moore KA, Stevenson JC, Carter KS, Bergstrom PW, et al. Assessing water quality with submersed aquatic vegetation. Bioscience 1993; 43: 86–94.

Lacoul P, Freedman B. Environmental influences on aquatic plants in freshwater ecosystems. Environ Rev 2006; 14: 89–136.

Bode A, Alvarez-Ossorio MT, Varela M. Phytoplankton and macrophyte contributions to littoral food webs in the Galician upwelling estimated from stable isotopes. Mar Ecol Prog Ser 2006; 318: 89–102.

Post DM. The long and short of food-chain length. Trends Ecol Evol 2002; 17: 269–277.

Takimoto G, Post DM. Environmental determinants of food-chain length: a meta-analysis. Ecol Res 2013; 28: 675–681.

Gerking SD. Feeding ecology of fish USA: Academic Press, 1994.

Feyrer F, Herbold B, Matern SA, Molye PB. Dietary shifts in a stressed fish assemblage: consequences of a bivalve invasion in the San Francisco Estuary. Environ Biol Fish 2003; 67: 277–288.

Quevedo M, Svanbäck R, Eklöv P. Intrapopulation niche partitioning in a generalist predator limits food web connectivity. Ecology 2009; 90: 2263–2274. PubMed

McMeans BC, McCann KS, Tunney TD, Fisk AT, Muir AM, Lester N, Shuter B, Rooney N. The adaptive capacity of lake food webs: from individuals to ecosystems. Ecol Monogr 2016; 86: 7–19.

Hayden B, Harrod C, Sonninen E, Kahilainen KK. Seasonal depletion of resources intensifies trophic interactions in subarctic freshwater fish communities. Freshw Biol 2015; 60: 1000–1015.

Castanheira MF, Herrera M, Costas B, Conceição LEC, Martins CIM. Can we predict personality in fish? Searching for consistency over time and across contexts. PLOS ONE; 8: e62037 doi: 10.1371/journal.pone.0062037 PubMed DOI PMC

Jackson AL, Inger R, Parnell AC, Bearhop S. Comparing isotopic niche widths among and within communities: SIBER–Stable Isotope Bayesian Ellipses in R. J Anim Ecol 2011; 80: 595–602. doi: 10.1111/j.1365-2656.2011.01806.x PubMed DOI

A non-lethal stable isotope analysis of valued freshwater predatory fish using blood and fin tissues as alternatives to muscle tissue

Trophic Position of the Species and Site Trophic State Affect Diet Niche and Individual Specialization: From Apex Predator to Herbivore

Contrasting structural complexity differentiate hunting strategy in an ambush apex predator

Impact of herbivory and competition on lake ecosystem structure: underwater experimental manipulation