DOI: 10.5061/dryad.mw6m90645
title: Data from: Phenotypic plasticity for sailfin mollies raised at two temperatures and three salinities

description: Phenotypic plasticity, the ability of a single genotype to produce
 different phenotypes under different environmental conditions, plays a
 profound role in several areas of evolutionary biology.  However,
 it is unclear how much reaction norms vary among conspecific populations
 and whether differences in reaction norms represent adaptations to
 different levels of environmental variation.  We present data on
 the reaction norms of growth and maturation to variation in temperature
 and salinity in sailfin mollies (Poecilia latipinna) from three
 populations from South Carolina (SC).  This area is the northern
 edge of the species range and we compare these reaction norms to those
 previously reported in populations from north Florida (NF), which is the
 center of the species range.  In general, fish from SC displayed
 less plasticity than fish from NF because they grew faster and matured
 earlier at the lower temperatures and salinities compared to NF
 fish.  Among fish from both regions, males were much less plastic
 than females.  In both sexes, fish from SC matured at much
 younger ages than NF fish in the same conditions.  While there
 was no detectable heterogeneity among populations from NF, males from one
 of the SC populations displayed a strikingly different response in age at
 maturity to temperature variation than did males from the other two SC
 populations, maturing earlier at the lower temperature, rather than at the
 higher one.  The pattern in fish from SC is one of
 countergradient variation, in which they grow faster and mature earlier in
 conditions that would otherwise slow growth and delay maturity. 
 This pattern is well-matched to the cooler thermal regime and shorter
 growing season experienced in SC populations, suggesting an adaptive
 divergence in reaction norms.
description: These data were collected from the F1 progreny of wild-caught
 fish raised in the laboratory under one of six combinations of two
 temperatures and three salinities.  This dataset comprises all of the raw
 data from these rearings.
description: # Data from: Phenotypic plasticity for sailfin mollies raised at two
 temperatures and three salinities
 [https://doi.org/10.5061/dryad.mw6m90645](https://doi.org/10.5061/dryad.mw6m90645) The data consist of records of individual fish from three different populations of origin raised in the laboratory. Each line or record describes one fish's history from parturition to maturation. In the experiment we raised fish under all combinations of two temperatures (24 or 29 degrees C) and three salinities (2, 12, or 20 parts per thousand). Each fish was raised individually in a 38 liter aquarium. We drew fish from three natural populations in South Carolina (Goat Island, Boundary, and Yawkey) and recorded where in the laboratory each fish's aquarium was placed (BAY) and its family identity (FAM, denoting progeny of a single female). ## Description of the data and file structure The variables are: ORIG: Individual population of origin. Entries are 1, 2, or 3, with 1 = Goat Island; 2 = Boundary; 3 = Yawkey. These populations are in coastal South Carolina and precise locations are described in the manuscript. FAM: Individual half-sib family identity. Each number corresponds to a half-sibship, which is the progeny of one female who likely mated with multiple males. Numbers are identifiers only and do not correspond perfectly to order of birth in the laboratory. TEMP: Temperature at which the fish was raised in the laboratory. Entries are 1 or 2 with 1 = 24 degrees C; 2 = 29 degrees C SAL: Salinity in parts per thousand at which the fish was raised in the laboratory. Entries are the actual salinities, 2, 12, or 20 parts per thousand. BAY: Location in the laboratory in which the fish's aquarium was located. Numbers correspond to a physical location in the laboratory. SIZE24: Standard length (tip of snout to caudal peduncle) in millimeters on day 24 after birth. SIZE 31: Standard length (tip of snout to caudal peduncle) in millimeters on day 31 after birth. SIZEMAT: Standard length (tip of snout to caudal peduncle) in millimeters at completion of maturation DTM: Number of days from birth to completion of maturation SEX: Sex of fish. Entries are either 1 or 2 with 1 = male; 2 = female Several cells are blank. These indicate missing data. The data are missing because the fish died during the course of the experiment.