On 29 April 2020, Johanna S. Kottmann will defend her PhD thesis. Due to COVID-19, the defence will take place online.
Using experimental trials and a combination of biochemical and molecular analysis tools, PhD student Johanna Sarah Kottmann, DTU Aqua has investigated maternal impacts on egg quality and early offspring performance in the European eel, a high-value species in aquaculture.
Assisted reproduction technologies have led to a steady production of eel eggs in captivity. Yet, variability in spawning success, egg quality and survival during embryonic stages hamper efficient production of viable eel larvae.
The studies of Johanna S. Kottmann and her colleagues provide new knowledge on the impacts of broodstock nutrition as well as hormonal treatments on egg quality and offspring developmental competence. The results underline the importance of a well-suited diet and long-term feeding in order to obtain strong embryos with high survival capacity. Also, hormones used to induce reproduction in captivity significantly influence the offspring developmental competence.
The experimental results of the studies are supported by molecular analyses. The analyses extensively explain observed morphological differences in offspring performance, thereby substantiating our knowledge about requirements for normal embryogenesis in European eel.
This knowledge is particularly important for European eel, because the early life stages remain unknown in nature, while meeting their natural requirements for healthy development is essential for development of captive breeding for aquaculture.
About the defence
Johanna S. Kottmann will defend her PhD thesis "Egg Quality and Offspring Performance in European Eel" on 29 April 2020 at 14.00 CEST.
The defence will be conducted online via Zoom. For a link to join the defence, please contact Rikke Hansen, rikh@aqua.dtu.dk, by 28 April 2020 15:00 CEST.
Supervisors
- Principal Supervisor: Senior Researcher Jonna Tomkiewicz, DTU Aqua
- Co-supervisor: Professor Helge Tveiten, UiT, Noway
Examiners
- Senior Researcher Manuel Gesto, DTU Aqua
- Professor Luz M. Perez, Universitat Politècnica de València, Spain
- Professor Carlos F. C. Lanes, University Federal of Pampa, Brazil
Chairperson at defence
- Senior Researcher Jane W. Behrens, DTU Aqua
A copy of the PhD thesis “Egg Quality and Offspring Performance in European Eel” may be obtained via e-mail.
Please send your request to Rikke Hansen, rikh@aqua.dtu.dk.