I am broadly interested in evolutionary biology, more particularly in the
evolution of cooperation. For my PhD, I use a comparative approach to
investigate what adaptations are specific to the ecology of the bluestreak
cleaner wrasse Labroides dimidiatus.
Whether in terms of morphology, physiology or behaviour, species are
usually very well adapted to their ecology. For example, fennec foxes are
extremely well adapted for the desert: their large ears increase the surface
to volume ratio and allow dissipating heat, their kidney restricts water loss
to the extent that they can live without free water and they are nocturnal and
build burrows to escape the excessive heat of the day. It thus appears that
natural selection shaped this species for its particular ecology. What about
species relying on cooperative interactions for their survival? Would they
adapt to their social environment just as other species adapt to harsh
The bluestreak cleaner wrasse feeds on the parasites of other fish
(referred to as ‘clients’), with up to 2000 interactions a day. The complex
social context that is paramount in the life of a cleaner may have selected
for a number of particular adaptations. Our group has extensively studied its
behaviour in the last decade and been able to show, amongst other things,
that these small fish are able to modulate their behaviour according to various
conditions, such as in biological market or image scoring situations.
Even though most of these adaptations have ecological relevance only for
cleaners, little comparative investigation has been done on whether related
species with different lifestyles might also be able to learn how to deal with
such situations. Furthermore, work on morphological adaptations is virtually
inexistent. Most of the species in the wrasse family (Labridae) have
completely different lifestyles and never engage in cleaning.
However, some species also do clean, but to a lesser extent and usually
only at the juvenile stage (facultative cleaners). The wrasse family thus provides
an optimal system for a comparative approach. I am comparing the behaviour,
cognitive capacities and some aspects of the morphology of L. dimidiatus
with related wrasse species (facultative cleaners or non-cleaners). This will
allow getting a better picture of the kind of selective pressures that shaped
a species whose lifestyle largely depends on social interactions.
More generally, this might help to understand how engaging down the path
of cooperation could impact the evolutionary history of a species.