DOI: 10.5061/dryad.ns1rn8ppq
title: Data from: Mate availability determines use of alternative reproductive phenotypes in hermaphrodites

description: In many species individuals can employ alternative reproductive
 phenotypes, with profound consequences for individual fitness and
 population dynamics. This is particularly relevant for self-compatible
 hermaphrodites, which have exceptionally many reproductive options. Here
 we investigated the occurrence of reproductive phenotypes in the
 simultaneously hermaphroditic freshwater snail Radix balthica under
 experimentally simulated conditions of low vs. moderate population
 density. We captured all mating behavior on camera and measured individual
 female lifetime reproductive success. We found every possible reproductive
 phenotype: (1) both male and female (i.e. truly hermaphroditic)
 reproduction, (2) purely female and (3) purely male reproduction, (4) male
 reproduction combined with self-fertilization and (5) female mating
 activity, (6) pure self‑fertilization without mating and (7-8) two types
 of reproductive failure. Variation in alternative reproductive phenotypes
 was explained by mate availability (10.8%) and individual condition,
 approximated by a snail’s mean daily growth rate (17.5%). Increased mate
 availability resulted in a lower diversity of reproductive phenotypes, in
 particular increasing the frequency of true hermaphrodites. However, it
 lowered phenotype-specific fecundities and hence reduced the population
 growth rate. Snails in better condition were more likely to reproduce as
 true hermaphrodites or pure females, while low-condition snails tended to
 suffer reproductive failure. Overall, we show substantial variation in
 alternative reproductive phenotypes in a hermaphrodite, which is possibly
 in part maintained by fluctuations in population density and thus mate
 availability, and by variation in individual condition. We also provide
 evidence of an almost two-fold increase in clutch size that can be
 ascribed specifically to mating as a female.
description: Please find this information in the manuscript and supporting
 information.
description: General note: Please also read the ReadMe files that accompany
 each dataset. They explain the column headers in each dataset.
 <strong>Focal individuals</strong>
 This file provides information about each of 268
 first-generation, laboratory-reared offspring of field-caught mothers,
 e.g., the experimental treatment snails experienced, the temporal block
 they were assigned to, the identity of their mother, their mean daily
 growth rate, lifetime reproductive phenotype, lifetime female reproductive
 output, and lifetime male and female mating success. Note that six of the
 274 snails that were subjected to laboratory mating trials were excluded
 from this file. Five snails were excluded because they were solely paired
 with a related snail, and one snail was excluded due to missing data on
 female reproductive output. The data in this file were used to produce
 Figs. 2 and 4 in the main manuscript, and Figs. S2, S4, S5 and S6 in the
 supporting information, as well as to write the Supporting Results 2
 (Randomness of reproductive patterns) and 4 (Relationship between female
 infertility and mating activity). <strong>Mating
 behavior</strong> This file provides information
 about the mating behavior of each of 215 snails, separately for each of
 the mating opportunities they were given. For each snail and mating
 opportunity, the file states the identity of the snail's mating
 partner, and whether the snail did not mate, mated just as a male, just as
 a female, or in both roles (i.e. sequentially reciprocally). Note that 53
 of the 268 snails included in the file "Focal individuals" were
 excluded from this file, because their mating behavior could not be
 assessed with very high accuracy. The data in this file were used to
 produce Fig. 3 in the main manuscript, and Fig. S3 in the supporting
 information. <strong>Clutch
 sizes</strong> This file provides information
 about 2117 egg clutches laid by 147 snails. For each clutch, the file
 includes, e.g., the identity of the clutch-laying snail, the date on which
 the clutch was collected from the snail, the number of eggs and developed
 embryos, and two classifications of clutches, one regarding the
 experimental treatment of the mother and one regarding the maternal mating
 behavior. Note that 10 of the 147 snails whose clutches are included in
 this file did not produce any eggs; these snails laid clutches that only
 consisted of jelly. One egg-laying snail (snail identity: 45_1.8) was
 excluded from this file because of an unknown growth rate. The data in
 this file were used to produce Fig. 5 in the main manuscript, and Fig. S7
 in the supporting information. <strong>Mating
 partner shell length</strong> This file provides
 information about 441 pairs of snails that were allowed to mate with one
 another in the course of the laboratory mating trial. For each pair, the
 file states, e.g., the identity of both mating partners, their shell
 lengths, and their mating activity. Note that 22 pairs of snails were
 excluded from this file, because the mating partners had the same mother
 and were thus related. The data in this file were used to write the
 Supporting Results 3 (Effects of size-matching first mating
 partners). <strong>Snail marking
 trial</strong> This file provides the results of
 a smaller laboratory experiment done to assess effects of marking snails
 individually on juvenile growth and survival after a two-week period. The
 snails used for this experiment were separate from those used in the
 mating trial. The file includes information about 30 marked and 20
 unmarked control snails. These data were used to write the Supporting
 Results 1 (Effects of marking on survival and growth), where more
 information about the experiment can be found. Note that 19 of the 50
 snails included in this trial originated from the study population
 (Uerikon, Lake Zurich, Switzerland), while 31 snails were from another
 population (Kilchberg) also located in Lake Zurich.