Intraspecific variation in the organismal stoichiometry of the Least Killifish tracks spatial variation in periphyton composition

Ecological stoichiometry, the mass-balance relationships in elemental composition among species in an ecosystem, is fundamental to understanding a wide variety of ecological phenomena, from foraging patterns to nutrient cycling (Sterner and Elser 2002). Variation in organismal stoichiometry, be it interspecific or intraspecific, can drive substantial variation in community and ecosystem dynamics (El Sabaawi et al. 2015, Des Roches et al. 2017, Leal et al. 2017a). Here we report a survey of the organismal stoichiometry and trophic niche of H. formosa in eight populations, four from each of two contrasting habitat types. First, we describe variation in water chemistry among a larger set of 17 locations, from which we selected our eight populations for study. We also document variation among these eight locations in the elemental composition of periphyton in the littoral zone, where H. formosa forage. Second, we describe the trophic niche of H. formosa in those eight populations*,* es..., We sampled water at 17 locations with populations of H. formosa. These locations embraced a variety of habitats, including springs, wooded swamps, open canopy lakes, and freshwater marshes. We selected eight of these locations for stoichiometric and stable isotope analyses: four freshwater springs (McBride’s Slough, Newport Bridge, Shepherd’s Spring, Wacissa River) and four lakes (Harper’s Eyelet, Little Lake Jackson, Moore Lake, Trout Pond). We chose these eight locations for two reasons. First, they spanned a wide range of water chemistry parameters. Second, the populations of H. formosa in these locations displays a wide range of population densities and life histories (Schrader and Travis 2012, Macrae and Travis 2014). 
We collected fish via dip netting in the shallow littoral zone, typically at depths less than 0.30 m. We sacrificed fish via rapid chilling in an ice slurry, following approved IACUC protocols. We obtained periphyton samples by scraping stems and leaves of aquat..., , # Intraspecific variation in the organismal stoichiometry of the Least Killifish tracks spatial variation in periphyton composition

[https://doi.org/10.5061/dryad.3n5tb2rt5](https://doi.org/10.5061/dryad.3n5tb2rt5)

## Description of the data and file structure

We sampled water at 17 locations with populations of *H. formosa*. We selected eight of these locations for stoichiometric and stable isotope analyses: four freshwater springs (McBride’s Slough, Newport Bridge, Shepherd’s Spring, Wacissa River) and four lakes (Harper’s Eyelet, Little Lake Jackson, Moore Lake, Trout Pond). We collected fish via dip netting and sacrificed fish via rapid chilling in an ice slurry, following approved IACUC protocols. We obtained periphyton samples by scraping stems and leaves of aquatic plants, larger rocks, and fallen limbs wherever we saw *H. formosa* individuals foraging. 

### Files and variables

#### File: 2010-2013_Water_Data.xlsx

**Description:** Water data collected from sites in the year...,