Henrik Christiansen visits EvoFish for his Master project

Henrik is doing his Master thesis on growth of bearded gobies using otoliths to estimate individual age and growth histories. Bearded goby is a key player in the Benguela Current ecosystem. Henrik hopes that growth patterns will shed light to the question whether goby males choose between "sneaker" and "nest guarding" life history strategies, or are all males opportunistic sneakers when young? 

Let Henrik to describe the project with his own words:

"After an interesting exchange semester last autumn in Bergen, I am happy to return here to work on my thesis project. Thanks to Anne Gro and my colleagues Maria and Yusra more than 1000 otoliths of the bearded goby are available for analysis. I want to reveal patterns in the growth of this ecological important species. Therefore I photograph the otoliths and analyse dimension characteristics as well as the formation of opaque and translucent increments indicating the age of the captured individual.

 

The northern Benguela ecosystem as a very challenging habitat surely affects the growth of the little gobies and I attempt to find out how e.g. oxygen saturation limits or benefits growth. Since Maria has found that the male gobies perform two different reproductive tactics, it would also be intriguing to know, if large males that defend nests are necessarily older than smaller males that sneak into nests to reproduce. Eventually I would like to polish some otoliths to also analyse daily increments, but before that many more hours in the otolith lab and work on the data analysis are necessary."

The project is supervised in Bergen by Anne Gro Vea Salvanes and Arild Folkvord.