DOI: 10.5061/dryad.rjdfn2z99
title: Life history and location data for Alfaro cultratus in 20 localities

description: Predation is known to have a significant effect on life history
 diversification in a variety of species. However, physical constraints of
 body shape and size can sometimes limit life history divergence. We test
 this idea in the Costa Rican livebearing fish Alfaro cultratus.
 Individuals in this species have a narrow body and keeled ventral surface,
 and females do not develop a distended abdomen when pregnant like other
 livebearing fishes. Here, we describe the life history of A. cultratus
 from 20 different populations across both high-predation and low-predation
 environments. We found significantly lower reproductive allotment in
 females from high-predation environments than in females from
 low-predation environments, but no significant difference in female or
 male size at maturity, number of offspring produced by females, or size of
 offspring. We found that A. cultratus exhibit isometric patterns of
 allocation for clutch dry mass in relation to female dry mass in
 high-predation and low-predation environments. Our results suggest that
 body shape constraints in this species limit the life history divergence
 we typically see between populations from high-predation and low-predation
 environments in other species.
description: We collected these fish over 3 different years (2006, 2007, and
 2019) from Costa Rica using a mesh seine. We euthanized the fish using
 MS-222 and then preserved them in 70% ethanol prior to dissection. We
 separated males and females and then we dissected the females on the left
 lateral side. We removed embryos and stomachs. We measured the length of
 the females (prior to dissection), staged the embryos according to the
 Haynes classification method (Haynes, J. L. (1995).
 Standardized Classification of Poeciliid Development for Life-History
 Studies. <i>Copeia</i> 1, 147–154.), and measured the dry mass
 of the females as well as the dry mass of the embryos for each female. We
 also calculated the average size for an embryo in each brood by dividing
 the dry mass of the embryos by the number of embryos in each brood.
 Information for an individual fish and the population it originates from
 is found in a single row. We looked at the length of males and females
 within the population to decide where the size at maturity was for each
 population. More details on methods can be found in our manuscript as well
 as in Johnson and Belk 2001 (Johnson, J. B., and Belk, M. C. (2001).
 Predation environment predicts divergent life-history phenotypes among
 populations of the livebearing fish Brachyrhaphis rhabdophora.
 <i>Oecologia</i> 126, 142–149. doi:10.1007/s004420000504.) We
 analyzed each life history trait in a linear model looking for the effects
 of predation. We incorporated covariates into the model. When
 analyzing number of offspring, we included female dry mass as a covariate.
 When analyzing offspring size and reproductive allotment, we used female
 dry mass and developmental stage of embryos as covariates. We did not
 include any covariates for male or female size at maturity. Brood dry mass
 was our measure of reproductive allotment. In addition, we log transformed
 reproductive allotment and number of offspring in the analysis to satisfy
 assumptions of the linear model.
description: Here is a key to the column names:  FieldID:
 This is a number used that shows the year and the site collected at by our
 lab group for that year. 19-15 would mean that the location was the 15th
 collected from in 2019.  Collection: This is a
 shorthand for fieldID that is used to differentiate the sites in the
 analysis. The numbers do not necessarily mean anything but they are
 grouped according to locality.  BYUID: the ID given to
 each individual fish that it is tagged with in the Monte L Bean
 Museum.  Length: Length in mm from the tip of the nose
 to the attachment of the caudal fin. Maturity: 1 means
 mature or an individual with developing embryos. 0 is immature. 
 DevStage: Development stage of embryos. This scale goes from 1-11
 and is explained in the Haynes article cited above. 
 NumOff: This is the number of offspring or count of developing
 embryos contained in a given female.  FemaleDryMass:
 This is the dry mass of the females with embryos and stomachs removed and
 24 hours in a dessication oven. This is measured in grams. 
 broodDryMass: This is the dry mass of the brood of a female after
 24 hours in a dessication oven. This is measured in grams. 
 Year: The year that the collections were made. 
 Locality: The name of the river or tributary where the
 collections were made.  Latitude
 Longitude Predation: 1 means predators were
 found while seining and 0 means they were not. 
 SizeMaturity: This was the size maturity of females in the
 population. This was decided as the mm length where over half of the
 females were mature in that size group.  N.Females:
 This is the number of mature females out of the number of collected
 females. N.Males: This is the number of collected
 males.  M.Mean.Size: This is the average length of the
 collected males which we used as the male size at maturity. 
 size: This is the brood dry mass divided by the number of embryos
 or the average size of embryos for each brood.