Genetic evidence for alloparental care and frequent multiple paternity in the brooding sea star (Leptasterias sp.)
Echinoderms form an abundant and ecologically important group of marine animals, and they are found in nearly every marine environment, from shallow tropical waters to deep polar benthos and even in the pelagic zone. They exhibit a wide diversity of reproductive strategies that range from broadcasting millions of gametes, with no parental care, to internal brooding of a few embryos for several weeks. While many echinoderm species have become model systems for studies of community ecology, evolutionary genetics, and development biology, very little is known about the distribution of mating and reproductive success in natural populations. In this study, we examined patterns of genetic maternity and paternity in the six-rayed sea star Leptasterias sp., an important predator of many intertidal communities and a species that exhibits maternal care of embryos. We used next-generation sequencing to rapidly develop informative microsatellite markers for this species, and used these markers to genotype 439 juveniles across 15 broods collected from the intertidal in Fogarty Creek, Oregon, USA. Our data show an unambiguous pattern of multiple paternity in all but one clutch examined, with some broods showing some of the highest levels of polyandry reported for a marine invertebrate. Moreover, we detected two cases of mixed maternity in which a female sea star carried another mother’s offspring mixed with her own. Alloparental care by females is rare, and since female Leptasterias do not eat during the 40–60 days brooding period, this expensive behavior may provide a useful system for examining the evolutionary costs and benefits of parental care in dynamic intertidal environments.
We thank Sarah Gravem for helpful comments on the manuscript, and Mark Dasenko for help with Illumina sequencing.
This research was supported by Oregon State University funds to F. S. B. and SURE Science internship funds to K. K. B.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All applicable international, national, and/or institutional guidelines for the care and use of animals were followed. This article does not contain any studies with human participants performed by any of the authors.
- Andrews S (2010) FastQC: a quality control tool for high throughput sequence data. http://www.bioinformatics.babraham.ac.ukprojectsfastqc. Accessed 22 Aug 2018
- Birkhead TR, Møller A (1992) Sperm competition in birds: evolutionary causes and consequences. Academic Press, New YorkGoogle Scholar
- Byrne M (1996) Viviparity and intragonadal cannibalism in the diminutive sea stars Patiriella vivipara and P. parvivipara (family Asterinidae). Mar Biol 125:551–567Google Scholar
- DeWoody JA, Fletcher DE, Wilkins SD, Avise JC (2000) Parentage and nest guarding in the tessellated darter (Etheostoma olmstedi) assayed by microsatellite markers (Perciformes: Percidae). Copeia 2000:740–747. https://doi.org/10.1643/0045-8511(2000)000%5b0740:pangit%5d2.0.co;2 CrossRefGoogle Scholar
- Jones AG, Walker D, Kvarnemo C et al (2001b) How cuckoldry can decrease the opportunity for sexual selection: data and theory from a genetic parentage analysis of the sand goby, Pomatoschistus minutus. Proc Natl Acad Sci USA 98:9151–9156. https://doi.org/10.1073/pnas.171310198 CrossRefPubMedGoogle Scholar
- Philipp DP, Gross MR (1994) Genetic evidence for cuckoldry in bluegill Lepomis macrochirus. Mol Ecol 3:563–569. https://doi.org/10.1111/j.1365-294x.1994.tb00087.x CrossRefGoogle Scholar
- Raymond M, Rousset F (1995) GENEPOP (version 1.2): population genetics software for exact tests and ecumenicism. J Hered 86:248–249. https://doi.org/10.1093/oxfordjournals.jhered.a111573 CrossRefGoogle Scholar
- Wilson WH (1991) Sexual reproductive modes in polychaetes: classification and diversity. Bull Mar Sci 48:500–516Google Scholar