Larval anuran developmental stoichiometry and areal biomass from geographically isolated wetlands in Georgia, USA

Raw data on larval anuran developmental stoichiometry across 11 species (Knapp_et_al_Stoichiometry_Dataset.xlsx) and larval anuran biomass data from four wetlands collected through throw sampling (Knapp_et_al_Biomass_Dataset.xlsx). All animal handling in this study was performed under The University of
Alabama Institutional Animal Care and Use Committee protocol ID 15-10-0110.
Study site

We conducted this study at the Jones
Center at Ichauway (hereafter Ichauway) located in Baker County, Georgia, USA.

Larval anuran
collection

We used a dip net (3-mm mesh size) to collect larval anurans intermittently
across the hydroperiod from February 2017 to September 2018 at the four study
GIWs. We timed our sampling to collect samples of all available larvae across
five developmental stages. The five stages were simplified [Column = Simplified Stages] as follows based on
Gosner (1960): Stage 1) no limbs (Gosner stages 23-25), Stage 1.5) developing
hindlimbs (Gosner stages 26-37), Stage 2) fully-developed hindlimbs (Gosner
stages 38-40), Stage 2.5) developing forelimbs (Gosner stage 41), and Stage 3)
developed forelimbs, but retaining a tail (Gosner stages 42-46; Fig. 1). We
euthanized larval anurans using 5 g/L tricaine methanesulfonate (MS-222)
solution and froze them at -20 °C for later
stoichiometric analysis.

Stoichiometric
analysis

We dissected euthanized larvae to remove
the gastrointestinal tract below the manicotto glandulare to the rectum, measured total length (body plus
tail) to the nearest 1 mm, and weighed larvae to the nearest 0.001 g. Whole-body
(body and tail) larval anurans were freeze-dried for ≥ 72 h, and then re-weighed to
determine larval dry-mass. We used either a mortar and pestle or a Retsch Mixer
Mill to homogenize dried larvae. To measure total
%C and total %N tissue content, we analyzed a ~1-3 mg subset of each homogenized
larva with a FLASH 2000 NC Analyzer. We combusted a further ~1-3 mg subset of each homogenized larva in a
Thermolyne muffle furnace at 500
°C for 1 h, digested each in 1 N HCl at 105 °C for 2 h, and used the ascorbic
acid-molybdate method to determine total %P. Larvae < 4 mg dry-mass were
homogenized together with like-species and stages collected from the same
wetland to increase particulate material for our analysis.

Larval anuran density, biomass, and nutrient
storage sampling

We measured biomass of larval
anurans monthly during the hydroperiods (March to June 2018) of the four study
wetlands using an aluminum 0.37 m2 throw trap. We sampled a minimum of 0.025% of
the wetland surface area (calculated from wetland
contour data and water-level data [Jones Center at Ichauway, unpublished
data]); throws were concentrated in water < 0.5 m in depth. For each
throw, larval anurans were removed from the trap using a dip net (3-mm mesh
size) and we continued dip netting until we had ten consecutive sweeps without
captures. Each larva was identified to species, measured for total length to
the nearest 1-mm, weighed to the nearest 0.01-g, assigned to one of five
developmental stage categories as described above [Column = Simplified Stages], and released.