Internal embryonic development in a non-copulatory, egg-laying teleost, the three-spined stickleback, Gasterosteus aculeatus

Dean, Laura L; Robertson, Shaun; Mahmud, Muayad; Maccoll, Andrew D C

Abstract

The switch from egg-laying to retaining and giving birth to live young is a major transition in the history of life. Despite its repeated evolution across the fishes, records of intermediate phenotypes are vanishingly rare, with only two known cases in existence of normally egg-laying fish species retaining embryos within the ovaries. We report the discovery of a third occurrence, in which well-developed embryos were found in the ovaries of a three-spined stickleback (Gasterosteus aculeatus), a non-copulatory, normally oviparous species. Extracted from the parent fish, these embryos hatched and grew to adulthood. Genetic and physiological examination of the parent fish and offspring ruled out development by parthenogenesis and hermaphroditism, therefore implicating internal fertilisation by a male stickleback. This extremely rare phenomenon may have been facilitated in this population by an unusual tendency for females to become egg-bound, and suggests that some major transitions may arise almost spontaneously.

Citation

Dean, L. L., Robertson, S., Mahmud, M., & Maccoll, A. D. C. (2019). Internal embryonic development in a non-copulatory, egg-laying teleost, the three-spined stickleback, Gasterosteus aculeatus. Scientific Reports, 9(1), Article 2395. https://doi.org/10.1038/s41598-019-38584-w

• Journal Article Type: Article
• Acceptance Date: Dec 28, 2018
• Online Publication Date: Feb 20, 2019
• Publication Date: 2019-12
• Deposit Date: Jan 17, 2019
• Publicly Available Date: Feb 21, 2019
• Journal: Scientific Reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 1
• Article Number: 2395
• DOI: https://doi.org/10.1038/s41598-019-38584-w
• Public URL: https://nottingham-repository.worktribe.com/output/1479773
• Publisher URL: https://www.nature.com/articles/s41598-019-38584-w