DOI: 10.5061/dryad.tx95x6b56
title: Data from: Consistent seasonal flexibility of the gut and its regions across wild populations of a winter-quiescent fish

description: Here, we investigated phenotypic flexibility in the size of the
 gastrointestinal (GI) tract across three northern populations of a
 winter-dormant warm-water fish, pumpkinseed sunfish (Lepomis gibbosus).
 The dried masses of all gut regions (stomach, pyloric caeca, intestine)
 were measured approximately biweekly between January and August 2021. In
 all populations, pumpkinseed exhibited pronounced structural flexibility
 in the GI tract, aligned with winter and the timing of reproduction. The
 dry mass of the GI increased by 1.3- to nearly 2.5-fold in the early
 spring. The pyloric caeca demonstrated the greatest capacity for
 flexibility, increasing by up to 3.7-fold prior to reproduction. In all
 populations, minimum dry GI mass was consistently achieved during winter
 and mid-summer. This capacity for gut flexibility may represent a novel
 mechanism for facilitating rapid adaptive responses (e.g., metabolic
 plasticity) to future environmental change.
description: Data are reported for female pumpkinseed sunfish from 60 to 110
 mm total length from three pond populations in Southern Ontario (GSP -
 Pond A, PP - Pond B, KSS - Pond C). Ponds are located on private property
 in King City, Ontario at the Koffler Scientific Reserve and Stouffville,
 Ontario. All fish were captured using rod-and-reel angling or clover fish
 traps baited with chicken-flavoured dog kibble. Fish were measured (0.1
 cm), weighed (0.001 g), and fully dissected to process and weigh all
 internal organs (digestive tract, liver, gonads, stomach contents). Data
 have been trimmed to include only information included in the
 analysis.
description: # Consistent seasonal flexibility of the gut and its regions across wild
 populations of a winter-quiescent fish
 [https://doi.org/10.5061/dryad.tx95x6b56](https://doi.org/10.5061/dryad.tx95x6b56) Data describe the lengths and masses of female pumpkinseed sunfish captured across three ponds in Southern Ontario, Canada, with approximately biweekly sampling events from January to August 2021. Data also include masses of dried gastrointestinal regions (stomach, pyloric caeca, intestine) that were used to evaluate structural flexibility of the digestive tract from winter to summer. Gastrointestinal tracts were extracted followed by sectioning at common constriction points. ## Description of the data and file structure GENERAL INFORMATION Date of data collection: January 2021 - August 2021 Each sampling event has a numeric code associated with its date, ranging from 1 to 15. Geographical location: Koffler Scientific Reserve, King City, Ontario, Canada and Stouffville, Ontario, Canada. Funding sources: Natural Sciences and Engineering Research Council of Canada, Discovery Grant and Canadian Graduate Scholarship Ancillary data: None Were data derived from other sources? No Additional data collected but not included in the current dataset: Full diet information, data describing male fish, data describing females outside of the target size range used for this study (60-110 mm), tissue protein content and egg characteristics DATA-SPECIFIC INFO Number of variables: 17 Number of cases/rows: 175 Missing data code: NA Variable list and description: Refer to the Metadata tab for a full description of all column headings and data categories. All masses are reported in grams and all lengths are reported in millimeters. Indices were calculated by dividing organ masses by body masses and are thus unitless.