A phylogenetic comparative analysis on the evolution of sequential hermaphroditism in seabreams (Teleostei : Sparidae)

Pla, S; Benvenuto, C; Capellini, I; Piferrer, F

Abstract

The Sparids are an ideal group of fish in which to study the evolution of sexual systems since they
exhibit a great sexual diversity, from gonochorism (separate sexes) to protandrous (male-first) and
protogynous (female-first) sequential hermaphroditism (sex-change). According to the size-advantage
model (SAM), selection should favour sex change when the second sex achieves greater reproductive
success at a larger body size than the first sex. Using phylogenetic comparative methods and a sample
of 68 sparid species, we show that protogyny and protandry evolve from gonochorism but evolutionary
transitions between these two forms of sequential hermaphroditism are unlikely to happen. Using male
gonadosomatic index (GSI) as a measure of investment in gametes and proxy for sperm competition,
we find that, while gonochoristic and protogynous species support the predictions of SAM, protandrous
species do not, as they exhibit higher GSI values than expected even after considering mating
systems and spawning modes. We suggest that small males of protandrous species have to invest
disproportionally more in sperm production than predicted not only when spawning in aggregations
with high levels of sperm competition, but also when spawning in pairs due to the need to fertilize
highly fecund females, much larger than themselves. We propose that this compensatory mechanism,
together with Bateman’s principles in sequential hermaphrodites, should be formally incorporated in
the SAM.

Citation

Pla, S., Benvenuto, C., Capellini, I., & Piferrer, F. (2020). A phylogenetic comparative analysis on the evolution of sequential hermaphroditism in seabreams (Teleostei : Sparidae). Scientific reports, 10, 3606. https://doi.org/10.1038/s41598-020-60376-w

• Journal Article Type: Article
• Acceptance Date: Jan 28, 2020
• Online Publication Date: Feb 27, 2020
• Publication Date: Feb 27, 2020
• Deposit Date: Feb 27, 2020
• Publicly Available Date: Feb 27, 2020
• Journal: Scientific Reports
• Print ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Volume: 10
• Pages: 3606
• DOI: https://doi.org/10.1038/s41598-020-60376-w
• Publisher URL: https://doi.org/10.1038/s41598-020-60376-w
• Related Public URLs: https://www.nature.com/srep/
• Additional Information: Funders : Spanish Government grant;Santander Travel Grant; Grant Number: GL2016-78710-R