Thesis subject

Student projects Molecular Ecology - Live-bearing fish

Are you interested in studying evolutionary processes at a molecular level? Are you interested the ecology & evolution in live-bearing fish from Costa Rica? Then this might be the right project for you!

In the live-bearing fish family Poeciliidae, which are well known for the guppy, many species have evolved a placenta. A placenta is an intimate structure of fusion between mother and offspring that is used for exchange of nutrients and hormones. Because of the evolution of a placenta, maternal provisioning shifts from before to after fertilization of the eggs. As placental females don’t have to invest in expensive eggs, this may enable them to depend less on mate choice (which otherwise could lead to mating closely related or dishonestly signalling males). Instead of mate choice based on appearance, placental females can ‘select’ a genetically acceptable father for their children by mating with multiple males and base the choice on sperm competition or on the growth of the embryos.

Therefore, it would be very interesting to study the effects of the evolution of the placenta on sexual selection in this live-bearing fish family. Several questions research questions are available: Does multiple paternity occur in placental fish species? And  in non-placental live-bearing fish species? Is multiple paternity correlated with superfetation (which is the ability to carry multiple  broods in different developmental stages)? How do environmental pressures  such as water visibility and predator regime, influence polyandry in placental fish? To answer these research questions molecular markers (microsatellites) will be used to perform paternity assessments. The projects can be performed starting from March 2017. They are best suited for MSc theses, but similar BSc projects can also be performed. For more information you can read this pdf or contact me via the contact forml!

Examiner: Prof. Dr. Ir. Johan L. van Leeuwen
Supervisors: Myrthe Dekker
Dr. Bart Pollux
Contact: Myrthe Dekker (via contact form)
Credits: dependent on project length
For: BSc/MSc Animal Sciences and Biology
(especially interesting for molecular ecology)