1
|
Felmy A, Streiff AB, Jokela J. Propensity for selfing varies within a population of hermaphroditic snails: coexistence of selfers, outcrossers and mixed-mating individuals. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230532. [PMID: 37800152 PMCID: PMC10548103 DOI: 10.1098/rsos.230532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 09/05/2023] [Indexed: 10/07/2023]
Abstract
To understand mating-system evolution in self-compatible hermaphrodites, variation in selfing rates is highly relevant. Empirical studies are rarely designed to capture variation between individuals, instead often comparing species and populations. Yet, evolution primarily occurs within populations, rendering among-individual variation essential. Observed individual selfing rates depend on the environment (e.g. differences in mate availability) and individuals' propensity for selfing. We quantified individual variation in selfing propensity in the snail Radix balthica by conducting laboratory mating trials that manipulated mate availability (low versus moderate) and estimating selfing rates from progeny arrays. We also measured female lifetime fitness. We found substantial among-individual variation in selfing propensity, including pure selfers (32%), pure outcrossers (31%) and mixed-mating individuals that selfed and outcrossed (37%). Experimental levels of mate availability did not significantly affect selfing rates. Selfers had reduced female liftetime fitness. Our results show that the propensity for selfing can differ considerably among individuals, with similar proportions of selfers, outcrossers and mixed maters. As mate availability did not affect selfing, our 'moderate' experimental level of mate availability might still have been too low to prompt selfers to outcross. This and the observed fitness differences also cautiously suggest that investigating the heritability of selfing propensities might be worthwhile in this population.
Collapse
Affiliation(s)
- Anja Felmy
- Department of Biology, Aquatic Ecology Unit, Lund University, 22362 Lund, Sweden
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- ETH Zurich, D-USYS, Institute of Integrative Biology, 8092 Zürich, Switzerland
| | - Alena B. Streiff
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- ETH Zurich, D-USYS, Institute of Integrative Biology, 8092 Zürich, Switzerland
| | - Jukka Jokela
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- ETH Zurich, D-USYS, Institute of Integrative Biology, 8092 Zürich, Switzerland
| |
Collapse
|
2
|
Felmy A, Weissert N, Travis J, Jokela J. Mate availability determines use of alternative reproductive phenotypes in hermaphrodites. Behav Ecol 2020. [DOI: 10.1093/beheco/araa046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
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 versus 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, whereas 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 2-fold increase in clutch size that can be ascribed specifically to mating as a female.
Collapse
Affiliation(s)
- Anja Felmy
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, Dübendorf, Switzerland
- ETH Zurich, D-USYS, Institute of Integrative Biology, Universitätstrasse 16, Zurich, Switzerland
- Department of Zoology, University of Oxford, Oxford, UK
| | - Nora Weissert
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, Dübendorf, Switzerland
| | - Joseph Travis
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Jukka Jokela
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, Dübendorf, Switzerland
- ETH Zurich, D-USYS, Institute of Integrative Biology, Universitätstrasse 16, Zurich, Switzerland
| |
Collapse
|
3
|
Norton CG, Wright MK. Strong first sperm precedence in the freshwater hermaphroditic snail Planorbella trivolvis. INVERTEBR REPROD DEV 2019. [DOI: 10.1080/07924259.2019.1630019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
4
|
Nakadera Y, Giannakara A, Ramm SA. Plastic expression of seminal fluid protein genes in a simultaneously hermaphroditic snail. Behav Ecol 2019. [DOI: 10.1093/beheco/arz027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Yumi Nakadera
- Evolutionary Biology Department, Bielefeld University, Germany Morgenbreede 45, 33615 Bielefeld, Germany
| | - Athina Giannakara
- Evolutionary Biology Department, Bielefeld University, Germany Morgenbreede 45, 33615 Bielefeld, Germany
| | - Steven A Ramm
- Evolutionary Biology Department, Bielefeld University, Germany Morgenbreede 45, 33615 Bielefeld, Germany
| |
Collapse
|