DOI: 10.5061/dryad.msbcc2g2r
title: Body mass index does not decline during winter for the sedentary marine gastropod Crepidula fornicata

description: Seasonal extremes in environmental conditions can substantially limit the
 growth and reproduction of animals. Sedentary marine animals are
 particularly susceptible to winter food limitation since they cannot
 relocate to more favorable conditions. In several temperate-zone bivalve
 species, substantial winter tissue mass declines have been documented;
 however, no comparable studies have been conducted on intertidal
 gastropods. Here, we investigate whether the suspension-feeding intertidal
 gastropod Crepidula fornicata also loses substantial tissue mass during
 the winter. We calculated body mass index (BMI) for individuals collected
 in New England at different times of year for seven years to determine
 whether BMI declines through winter or varies seasonally. Remarkably, C.
 fornicata body mass did not decline significantly during winter months;
 indeed, a relatively poorer body condition was associated with higher
 seawater temperature, higher air temperature and higher chlorophyll
 concentration. In a laboratory experiment, we found that C. fornicata
 adults that were not fed for three weeks at 6 °C (local winter seawater
 temperature) showed no detectable declines in BMI compared to field
 collected individuals. Future studies should document energy budgets of C.
 fornicata and other sedentary marine animals at low winter seawater
 temperatures, and the impact of short-term elevated temperatures on those
 energy budgets.
description: #### Body mass index does not decline during winter for the sedentary
 marine gastropod Crepidula fornicata Authors: Amanda M. Franklin, Alberto
 Rivera, Justin Robbins, Jan A. Pechenik File: **data_BMI.csv**
 Description: Length and weight data used to calculate BMI Column headers:
 * Shell Length mm: shell length in mm * Dry tissue weight mg: dry tissue
 weight in mg * Location: location that Crepidula fornicata were collected
 * Date: date that Crepidula fornicata were collected File:
 **data_envvar.csv** Description: Environmental data for each collection
 location and date Column headers: * Date: date that Crepidula fornicata
 were collected * Location: location that Crepidula fornicata were
 collected * total measured: number of C. fornicata measured * OISST_daily:
 daily sea surface temperature in degrees celsius * WebpageSST: source for
 daily sea surface temperature * Chlorophyll_monthly: monthly chlorophyll a
 concentration in mg per L * Webpage_Chlorophyll: source for monthly
 chlorophyll a concentration * SST_Monthly: monthly sea surface temperature
 in degrees celsius * Webpage_monthlySST: source for monthly sea surface
 temperature * AirT_MonthlyAvg: monthly average air temperature in degrees
 celsius * AirT_website: source for monthly average air temperature File:
 **data_starvation.csv** Description: Data for the starvation experiment
 conducted in the laboratory Column headers: * Exp: Date experiment was
 conducted * Treatment: treatment group for individual C. fornicata. Either
 fielddata (measured immediately upon collection), no food * for 3 weeks or
 food for 3 weeks. * Shell Length mm: shell length in mm * Dry weight mg:
 dry tissue weight in mg * Location: location that Crepidula fornicata were
 collected