Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Jul 18;7(1):5770.
doi: 10.1038/s41598-017-06163-6.

Population variation in the trophic niche of the Trinidadian guppy from different predation regimes

Eugenia Zandonà  1   2 , Christopher M Dalton  3 , Rana W El-Sabaawi  3   4 , Jason L Howard  5   6 , Michael C Marshall  7 , Susan S Kilham  5 , David N Reznick  8 , Joseph Travis  9 , Tyler J Kohler  10   11 , Alexander S Flecker  3 , Steven A Thomas  10 , Catherine M Pringle  7
Affiliations

Population variation in the trophic niche of the Trinidadian guppy from different predation regimes

Eugenia Zandonà et al. Sci Rep. .

Abstract

Population variation in trophic niche is widespread among organisms and is of increasing interest given its role in both speciation and adaptation to changing environments. Trinidadian guppies (Poecilia reticulata) inhabiting stream reaches with different predation regimes have rapidly evolved divergent life history traits. Here, we investigated the effects of both predation and resource availability on guppy trophic niches by evaluating their gut contents, resource standing stocks, and δ15N and δ13C stable isotopes across five streams during the wet season. We found that guppies from low predation (LP) sites had a consistently higher trophic position and proportion of invertebrates in their guts and assimilate less epilithon than guppies from high predation (HP) sites. Higher trophic position was also associated with lower benthic invertebrate availability. Our results suggest that LP guppies could be more efficient invertebrate consumers, possibly as an evolutionary response to greater intraspecific competition for higher quality food. This may be intensified by seasonality, as wet season conditions can alter resource availability, feeding rates, and the intensity of intraspecific competition. Understanding how guppy diets vary among communities is critical to elucidating the role of niche shifts in mediating the link between environmental change and the evolution of life histories.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Figure 1
Figure 1
Map showing study rivers. (1) Marianne; (2) Arima; (3) Guanapo; (4) Aripo; (5) Quare. Streams constituting the Caroni drainage are in blue, the Oropuche (Quare only) in red, and the Marianne in green. Modified from El-Sabaawi et al. 2012.
Figure 2
Figure 2
Proportion diet composition measured from the gut contents of HP and LP guppies from the Arima and Quare rivers. Data represent the estimated marginal means calculated by the GLM on arcsin transformed data, and have been back-transformed for the graphical representation. Food categories are invertebrates (dark grey), amorphous detritus (white), and algae (light grey).
Figure 3
Figure 3
Relationship between fish length and proportion of invertebrates and detritus in diet from the Arima and Quare rivers. Only significant relationships are shown. HP guppies: filled symbols; LP guppies: open symbols.
Figure 4
Figure 4
Top: Guppy trophic position across HP and LP sites in the five studied streams. Bottom: Relationship between guppy trophic position and invertebrate biomass in the five studied streams. HP guppies: filled symbols; LP guppies: open symbols. Values are averages of raw data. Error bars are ±1 standard error.
Figure 5
Figure 5
Proportion of different diet items contributing to guppy diet in HP (black) and LP (grey) sites. Data are proportions calculated from stable isotopes by the SIAR program, and error bars indicate standard errors. Pred = invertebrate predators; Coll = invertebrate collectors; Graz = invertebrate grazers; Shred = invertebrate shredders; Epi = epilithon.
See this image and copyright information in PMC

References

    1. Martin RA, Pfennig DW. Disruptive selection in natural populations: the roles of ecological specialization and resource competition. American Naturalist. 2009;174:268–281. doi: 10.1086/600090. - DOI - PubMed
    1. Whiteley AR. Trophic polymorphism in a riverine fish: morphological, dietary, and genetic analysis of mountain whitefish. Biological Journal of the Linnean Society. 2007;92:253–267. doi: 10.1111/j.1095-8312.2007.00845.x. - DOI
    1. Smith TB. Bill size polymorphism and intraspecific niche utilization in an african finch. Nature. 1987;329:717–719. doi: 10.1038/329717a0. - DOI
    1. Svanback R, Eklov P. Morphology in perch affects habitat specific feeding efficiency. Functional Ecology. 2004;18:503–510. doi: 10.1111/j.0269-8463.2004.00858.x. - DOI
    1. Robinson BW, Wilson DS. Character release and displacement in fishes - A neglected literature. American Naturalist. 1994;144:596–627. doi: 10.1086/285696. - DOI

Publication types