Evolutionary Biology
Schärer Group
Group Members
Main Questions
Current Research
Former Research
Research Methods

Schärer Group
Evolutionary Biology
Zoological Institute
University of Basel
Vesalgasse 1
CH-4051 Basel

Lucas Marie-Orleach

email: l.marie-orleach@unibas.ch
phone: +41 61 267 03 75
fax: +41 61 267 03 62

I am a Postdoc in the research group of Lukas Schärer and I investigate processes of sexual selection in a simultaneous hermaphrodite, Macrostomum lignano.

Current research

I am interested in evolutionary forces that shape the reproductive success of an individual, at both the pre-copulatory and the post-copulatory stages. Several features of M. lignano as well as laboratory techniques make this organism very suitable and powerful to study mating behaviour, sperm transfer and offspring production. Specifically, my studies focus on copulatory and post-copulatory behaviour and sexual conflict, the operation of sexual selection along consecutive episodes of selection, and the genetic basis of siring success.

Pictures of the sperm-receiving organ of a worm (630x).
Under bright field illumination (left picture), we see the total number of received sperm (~14 sperm cells).
Under epifluorescence illumination (right picture), we see the single sperm coming from a GFP-positive individual.

Former research

During my Master, I studied sexual selection in the alternative male reproductive tactic of Atlantic salmon, specifically the link between the colouration of sneakers and their genetic quality. Results indicated that darker individuals sired offspring that had a higher survival but also, a delayed emergence. The experiments were performed at the INRA of Rennes, and supervised by Guillaume Evanno and Jean-Marc Roussel.

Pictures of Atlantic salmon eggs (left picture), alevin (middle picture) and male's skin (right picture).

Curriculum vitae

Born in 1986 in Bayeux, France.

2014 to present

Postdoc in Evolutionary Biology, University of Basel.


Ph.D. in Evolutionary Biology, University of Basel.


M.Sc. in Behavioural and Evolutionary Ecology, University of Rennes 1.


B.Sc. in Biology of Organisms, University of Caen.


Marie-Orleach L, Janicke T, Vizoso DB, Eichmann M and Schärer L, 2014. Fluorescent sperm in a transparent worm: validation of a GFP marker to study sexual selection. BMC Evol. Biol. 14: 148. (link)

Marie-Orleach L, Roussel J-M, Bugeon J, Tremblay J, Ombredane D and Evanno G, 2014. Melanin-based coloration of sneaker male Atlantic salmon is linked to the viability and emergence timing of their offspring. Biol. J. Linn. Soc. 111: 126-135.(link)

• Janicke T, Marie-Orleach L, De Mulder K, Berezikov E, Ladurner P, Vizoso DB and Schärer L, 2013. Sex allocation adjustment to mating group size in a simultaneous hermaphrodite. Evolution 67: 3233-3242. (link)

Marie-Orleach L, Janicke T and Schärer L, 2013. Effects of mating status on copulatory and post-copulatory behaviour in a simultaneous hermaphrodite. Anim. Behav. 85: 453-461. (link)

• Mander L, Marie-Orleach L and Elliott M, 2013. The value of wader foraging behaviour study to assess the success of restored intertidal areas. Est. Coast. Shelf Sci. 131: 1-5. (link)

this page was last updated on Monday, June 30, 2014