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| | | afdeling: | | | Departement Biologie | | interne mandaten: | | | | | bedrijfsadres: | | | Campus Drie Eiken
D.C.106
Universiteitsplein 1
2610 Wilrijk
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I worked as a postdoctoral fellow of the fund for scientific research Flanders-Belgium (FWO-Vl) from 2006 until September 2012 at the Laboratory
for Functional Morphology at the University of Antwerp, where the evolution of form and function in vertebrate
musculo-skeletal systems is studied. I am currently a post-doc reseach assistent at Ghent University in the Evolutionary Morphology of Vertebrates laboratory. My research focuses on the biomechanics of the feeding apparatus in fishes. I am particularly intrigued by the large diversity in cranial morphology in this group of animals. The most common strategy for fish to capture prey is by generating suction. They do this by
rapidly increasing the volume of the mouth cavity, thereby drawing water and prey towards, and into the mouth. Although many fish species
share this strategy to capture prey, evolution has resulted in a tremendous variation in the size, shape, and mechanical properties of the individual
elements composing the complex heads of suction feeding fish. Understanding why we see such large morphological diversity in the feeding systems of
suction feeders, despite that they are all subject to the same physical laws, is the overall goal of my research.
 As a doctoral student (supervised by dr.
Anthony Herrel and dr.
Peter Aerts) , I studied the consequences
of the remarkably increased size of the jaw muscles in different species
of African air-breathing catfish on the mechanics of their feeding
apparatus. By combining experimental work (high-speed
video, X-ray video) with mathematical modelling (forward and inverse
dynamics), my supervisors and I dealt with different aspects of the
process of prey capture in these fish. More
information on my PhD-thesis can be found here. |  One of my ongoing projects focusses on probably one of the most specialized suction
feeders: pipefishes and seahorses (Family Syngnathidae). Their
morphology differs greatly from any other suction feeding fish, which
makes this
group particularly suitable to study the hydrodynamic constraints on the
evolution of cranial systems in fish. As part of a
morphological-biomechanical collaboration between the University of
Ghent (dr.
Dominique Adriaens), the Antwerp
Zoo and our functional morphology lab (see also the project page of Gert
Roos), I will investigate the biomechanics (and hydrodynamics) of
the interaction between syngnathid fish and their aquatic environment
during feeding. Results of this study can be found on my publications web-page.
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the goals is also to improve the accuracy of the currently applied
biomechanical models to study the hydrodynamics of prey capture by
making use of computational fluid dynamics (CFD). To
do so, I will make use of FLUENT
software the solve the set of Navier-Stokes equations (a system of
3-dimensional, non-linear, coupled differential equations) and
continuity equations that describe the flow of water resulting from the
displacement and expansion of the feeding system of the fish during prey
capture. Since interaction with the surrounding water
is critical for a fish trying to suck a prey, this analysis will
hopefully learn us more on how suction feeding works. More information
on vertebrate suction models and some results from CFD can be found in
this review-discussion article (full-text
pdf). |  If we want to understand the advantages of suction feeding, it is more
than interesting to study animals that manage to capture prey without
generating suction. Semi-aquatic snakes like Natrix tessellata
strike at prey by rapidly accelerating their head towards the prey with
their mouth opened widely. In collaboration with Jonathan
Brecko and the 3D scanning facilities at Xios
Limburg, the hydrodynamics of non-suction underwater prey capture is
studied by CFD modelling. |  As air is about 800 times less dense than water, a suction-induced airflow will no longer cause prey displacement. This is particularly intriguing since the acquisition of a terrestrial life-style is one of the key events in the evolution of vertebrates. A few years ago, I performed a study on terrestrial feeding in the eel-catfish. Now, terrestrial feeding kinematics in mudskippers is being investigated using high-speed X-ray video. I am the promotor of the doctoral thesis work of Krijn Michel. Recently, Science magazine reported about my research on this topic in their Meeting Briefs section (pdf).
 By analysing prey-capture kinematics of a specialist piscovore (asp Aspius aspius) during feeding on untethered, live goldfish, it appeared that significant modulation of prey capture kinematics occurs in function of the escape attempts of prey. I tested whether this modulation is possible due to a feedforward or a feedback neuromotorical control mechanism. These results were recently published in the journal Zoology (Elsevier) (full-text pdf).
 Boxfishes (Teleostei: Ostraciidae) are marine fishes having rigid carapaces that vary significantly among taxa in their shapes and structural ornamentation. CFD simulations of flow around the carapax of multiple boxfish species are being performed. The aim is to understand the hydrodynamic consequences of variation in carapax shape, and how this evolved within the boxfish clade. This project is a collaboration with dr. Michael Alfaro & Tina Marcroft (UCLA) and dr. Eize Stamhuis (Univ. Groningen & Univ. Bremen).
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contact
info: Sam Van Wassenbergh, Universiteit Antwerpen (Dept. Biology),
Universiteitsplein 1, B-2610 Antwerpen, Belgium. Tel: +32 3 265 22 60 Fax:
+32 3 265 22 71 Email: sam.vanwassenbergh@ua.ac.be
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