Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Records 1 - 20 / 39

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: q=Fleuren
Check title to add to marked list
Data from: Coasting in live-bearing fish: the drag penalty of being pregnant
Quicazan Rubio, E.M. ; Leeuwen, J.L. van; Manen, Klaas Van; Fleuren, M. ; Pollux, B.J.A. ; Stamhuis, Eize J. - \ 2019
viviparity - swimming - biomechanics - PIV - Live-bearing
Swimming performance of pregnant live-bearing fish is presumably constrained by the additional drag associated with the reproductive burden. Yet, it is still unclear how and to what extent the reproductive investment affects body drag of the females. We examined the effect of different levels of reproductive investment on body drag. The biggest measured increase in body volume due to pregnancy was about 43%, linked to a wetted area increase of about 16% and 69% for the frontal area. We printed three-dimensional models of live-bearing fish in a straight body posture representing different reproductive allocation (RA) levels. We measured the drag and visualized the flow around these models in a flow tunnel at different speeds. Drag grew in a power fashion with speed and exponentially with the increase of RA, thus drag penalty for becoming thicker was relatively low for low speeds compared to high ones. We show that the drag increase with increasing RA was most probably due to bigger regions of flow separation behind the enlarged belly. We suggest that the rising drag penalty with an increasing RA, possibly together with pregnancy-related negative effects on muscle- and abdominal bending performance, will reduce the maximum swimming speed.
Coasting in live-bearing fish: The drag penalty of being pregnant
Quicazan-Rubio, Elsa M. ; Leeuwen, Johan L. Van; Manen, Klaas Van; Fleuren, Mike ; Pollux, Bart J.A. ; Stamhuis, Eize J. - \ 2019
Journal of the Royal Society, Interface 16 (2019)151. - ISSN 1742-5689
Biomechanics - Particle image velocimetry - Reproductive allocation - Swimming

Swimming performance of pregnant live-bearing fish is presumably constrained by the additional drag associated with the reproductive burden. Yet, it is still unclear how and to what extent the reproductive investment affects body drag of the females. We examined the effect of different levels of reproductive investment on body drag. The biggest measured increase in body volume due to pregnancy was about 43%, linked to a wetted area increase of about 16% and 69% for the frontal area. We printed three-dimensional models of live-bearing fish in a straight body posture representing different reproductive allocation (RA) levels. We measured the drag and visualized the flow around these models in a flow tunnel at different speeds. Drag grew in a power fashion with speed and exponentially with the increase of RA, thus drag penalty for becoming thicker was relatively low for low speeds compared to high ones. We show that the drag increase with increasing RA was most probably due to bigger regions of flow separation behind the enlarged belly. We suggest that the rising drag penalty with an increasing RA, possibly together with pregnancy-related negative effects on muscle- and abdominal bending performance, will reduce the maximum swimming speed.

Resilience of aquatic systems under biological invasions
Nagelkerke, L.A.J. ; Pollux, B.J.A. ; Fleuren, M. - \ 2018
- 1 p.
Resilience of aquatic ecosystems under biological invasions
Nagelkerke, L.A.J. ; Fleuren, M. ; Pollux, B.J.A. - \ 2018
Functional morphological adaptations in invasive round goby (Neogobius melanostomus) populations across Europe
Fleuren, M. ; Pollux, B.J.A. ; Nagelkerke, L.A.J. - \ 2018
Functional morphological adaptations in invasive round goby (Neogobius melanostomus) populations across Europe
Fleuren, M. ; Pollux, B.J.A. ; Nagelkerke, L.A.J. - \ 2018
The adaptive benefit of superfetation in live-bearing fishes: a slender body leads to improved escape performance
Fleuren, M. ; Leeuwen, J.L. van; Pollux, B.J.A. - \ 2018
Evolution through the lens of biomechanics: morphology, locomotion and reproductive traits.
Fleuren, Mike - \ 2018
They came, they changed, they conquered: the role of adjustment to unfamiliar environments in biological invasions
Fleuren, M. ; Pollux, B.J.A. ; Nagelkerke, L.A.J. - \ 2018
Evolution through the lens of biomechanics: morphology, locomotion and reproductive traits
Fleuren, Mike - \ 2018
Data from: Three-dimensional analysis of the fast-start escape response of the least killifish, Heterandria formosa
Fleuren, M. ; Leeuwen, J.L. van; Quicazan Rubio, E.M. ; Pieters, R.P.M. ; Pollux, B.J.A. ; Voesenek, C.J. - \ 2018
3D tracking - C start - biomechanics - fish behaviour - swimming - Heterandria formosa
Fish make C-starts to evade predator strikes. Double-bend (DB) C-starts consist of three stages: Stage 1, in which the fish rapidly bends into a C-shape; Stage 2, in which the fish bends in the opposite direction; and a variable Stage 3. In single-bend (SB) C-starts, the fish immediately straightens after Stage 1. Despite fish moving in 3D space, fast-start responses of adult fish have mainly been studied in a horizontal plane. Using automated 3D tracking of multi-camera high-speed video sequences, we show that both SB and DB fast-starts by adult female least killifish (Heterandria formosa) often contain a significant vertical velocity component, and large changes in pitch (DB: up to 43 deg) and roll (DB: up to 77 deg) angles. Upwards and downwards elevation changes are correlated with changes in pitch angle of the head; movement in the horizontal plane is correlated with changes in yaw angle of the head. With respect to the stimulus, escape heading correlates with the elevation of the fish at the onset of motion. Irrespective of the initial orientation, fish can escape in any horizontal direction. In many cases, the centre of mass barely accelerates during Stage 1. However, it does accelerate in the final direction of the escape in other instances, indicating that Stage 1 can serve a propulsive role in addition to its preparatory role for Stage 2. Our findings highlight the importance of large-scale 3D analyses of fast-start manoeuvres of adult fish in uncovering the versatility of fish escape repertoire.
Why do placentas evolve? Evidence for a morphological advantage during pregnancy in live-bearing fish
Fleuren, Mike ; Quicazan-Rubio, Elsa M. ; Leeuwen, Johan L. van; Pollux, Bart J.A. - \ 2018
PLoS ONE 13 (2018)4. - ISSN 1932-6203
A live-bearing reproductive strategy can induce large morphological changes in the mother during pregnancy. The evolution of the placenta in swimming animals involves a shift in the timing of maternal provisioning from pre-fertilization (females supply their eggs with sufficient yolk reserves prior to fertilization) to post-fertilization (females provide all nutrients via a placenta during the pregnancy). It has been hypothesised that this shift, associated with the evolution of the placenta, should confer a morphological advantage to the females leading to a more slender body shape during the early stages of pregnancy. We tested this hypothesis by quantifying three-dimensional shape and volume changes during pregnancy and in full-grown virgin controls of two species within the live-bearing fish family Poeciliidae: Poeciliopsis gracilis (non-placental) and Poeciliopsis turneri (placental). We show that P. turneri is more slender than P. gracilis at the beginning of the interbrood interval and in virgins, and that these differences diminish towards the end of pregnancy. This study provides the first evidence for an adaptive morphological advantage of the placenta in live-bearing fish. A similar morphological benefit could drive the evolution of placentas in other live-bearing (swimming) animal lineages.
Three-dimensional analysis of the fast-start escape response of the least killifish, Heterandria formosa
Fleuren, Mike ; Leeuwen, Johan L. van; Quicazan-Rubio, Elsa M. ; Pieters, Remco P.M. ; Pollux, Bart J.A. ; Voesenek, Cees J. - \ 2018
Journal of Experimental Biology 221 (2018)7. - ISSN 0022-0949
3D tracking - Biomechanics - C-start - Fish behaviour - Poeciliidae - Swimming
Fish make C-starts to evade predator strikes. Double-bend (DB) C-starts consist of three stages: Stage 1, in which the fish rapidly bends into a C-shape; Stage 2, in which the fish bends in the opposite direction; and a variable Stage 3. In single-bend (SB) C-starts, the fish immediately straightens after Stage 1. Despite fish moving in threedimensional (3D) space, fast-start responses of adult fish have mainly been studied in a horizontal plane. Using automated 3D tracking of multi-camera high-speed video sequences, we show that both SB and DB fast-starts by adult female least killifish (Heterandria formosa) often contain a significant vertical velocity component, and large changes in pitch (DB up to 43 deg) and roll (DB up to 77 deg) angles. Upwards and downwards elevation changes are correlated with changes in pitch angle of the head; movement in the horizontal plane is correlated with changes in yaw angle of the head. With respect to the stimulus, escape heading correlates with the elevation of the fish at the onset of motion. Irrespective of the initial orientation, fish can escape in any horizontal direction. In many cases, the centre of mass barely accelerates during Stage 1. However, it does accelerate in the final direction of the escape in other instances, indicating that Stage 1 can serve a propulsive role in addition to its preparatory role for Stage 2. Our findings highlight the importance of large-scale 3D analyses of fast-start manoeuvres of adult fish in uncovering the versatility of fish escape repertoire.
Redefining the ‘super’ in superfetation: Are pregnant live bearing fish with more superfetation better swimmers?
Fleuren, M. ; Leeuwen, J.L. van; Pollux, B.J.A. - \ 2017
Reproductive adaptations to reduce locomotor costs in viviparous fish (Poeciliidae)
Fleuren, Mike - \ 2017
Wageningen University. Promotor(en): J.L. van Leeuwen, co-promotor(en): B.J.A. Pollux. - Wageningen : Wageningen University - ISBN 9789463438025 - 204
fishes - poeciliidae - reproduction - adaptation - vivipary - locomotion - biomechanics - zoology - vissen - poeciliidae - voortplanting - adaptatie - levendbarend - voortbeweging - biomechanica - zoölogie

Viviparity, a live-bearing mode of reproduction, has evolved over 100 times independently in vertebrate animals. Despite its frequent evolution, viviparity has a number of hypothesised disadvantages compared to the ancestral mode of reproduction, oviparity (egg-laying). One of these disadvantages is a reduction in locomotor performance during pregnancy, the period of internal development of the embryos. Adaptations to a live-bearing reproductive mode could have evolved to reduce these locomotor costs. In this thesis, I aim to find whether matrotrophy, post-fertilization nutrient provisioning (e.g. through a placental structure), and superfetation, the presence of multiple broods of different developmental stages, reduce the locomotor performance decline during pregnancy in the Poeciliidae, live-bearing fishes.

In Chapter 2, we review the literature on the effects of pregnancy on morphology, performance and fitness. The biomechanics of each mode of locomotion (walking, swimming or flying) are distinct, and are affected differently by the added mass and volume of pregnancy. Furthermore, we list the possible adaptations that have evolved to reduce the locomotor costs of pregnancy, and divide them into three different categories: adaptations that reduce the locomotor costs of live-bearing, adaptations with which the locomotor costs of live-bearing are avoided, and adaptations to the life history of the animal. Lastly, we discuss hiatuses in the literature and experimental procedures to quantify the hypothesised benefit of adaptations.

In Chapter 3, we compare the morphological changes during pregnancy in two closely-related species of live-bearing fish: Poeciliopsis turneri and Poeciliopsis gracilis. These species mainly differ in their mode of nutrient provisioning: P. gracilis is lecithotrophic and P. turneri is an extensive matrotroph. We tracked the morphological changes in 3D using a non-invasive method that creates three-dimensional body models. We find that P. turneri is more slender during the early stages of pregnancy, but increase in size more rapidly. This is in line with the locomotor costs hypothesis, which predicts that matrotrophic fish are more slender during the early stages of pregnancy, but that the difference between the body shapes of lecithotrophic and matrotrophic fish diminishes as pregnancy progresses. Our results indicate that matrotrophy could indeed provide a morphological advantage during pregnancy.

Fast-start performance, a manoeuvre fish deploy to escape predatory strikes, is important for individual survival. In Chapter 4, we use state-of-the-art biomechanical methods to, for the first time, quantify this manoeuvre in three-dimensional space in adult fish (Heterandria formosa). We show that fish can orient their escapes in up- and downwards direction, and that this is correlated with a change in pitch angle of the body. Changes in roll angle of the body were not correlated with orientation of the fish. We furthermore demonstrate that stage 1 of the fast start, often described as a preparatory stage, can already contribute to propulsion. The results from Chapter 4 indicate that three-dimensional measurements of fast-start manoeuvres provide novel insights that were often overlooked.

Measuring fast starts in three-dimensional space is relevant in determining the adverse effects of pregnancy on locomotor performance. We did this by comparing three species of live-bearing fish: P. turneri, H. formosa and Phalloptychus januarius. In Chapter 5, we show that pregnancy-induced changes in abdominal width are correlated with a reduction in performance in the horizontal plane (maximal horizontal speed, change in yaw angle), but less so in the vertical plane (maximal vertical speed, change in pitch angle). Furthermore, we demonstrate that an increase in abdominal width is correlated with a decrease in abdominal curvature and, for some species, in a decrease in maximal curvature rate in the abdomen. Lastly, we show that the pregnancy-induced morphological changes depend on the level of superfetation: species with a high level of superfetation experience higher frequency, but smaller amplitude changes in the shape of the abdomen. Whether superfetation actually results in a more slender body shape, as predicted by the locomotor costs hypothesis, depends on the level of reproductive investment.

In this thesis, I show that pregnancy induces changes in morphology which comes with a cost in fast-start performance. Both matrotrophy and superfetation affect how body shape changes due to pregnancy, but whether the latter provides beneficial changes depends on the level of reproductive investment. Furthermore, I reveal that fast starts can have a substantial three-dimensional component which is relevant both to biomechanicists that aim to understand the physical and physiological mechanisms underlying this manoeuvre and to evolutionary biologists that strive to answer performance-related questions.

Morphology and 3D fast-start escape performance of pregnant and virgin live-bearing fish
Fleuren, M. ; Leeuwen, J.L. van; Pollux, B.J.A. - \ 2016
Pregnant as a prey: performance and kinematics of the 3D fast-start escape response of live-bearing fish
Fleuren, M. ; Leeuwen, J.L. van; Pollux, B.J.A. - \ 2016
The effect of pregnancy on escape response in live-bearing fish: methology and preliminary results
Fleuren, M. ; Leeuwen, J.L. van; Pollux, B.J.A. - \ 2015
Análisis en 3D de la respuesta de escape para estudiar la evolución de la placentación en peces poecílidos
Quicazan Rubio, E.M. ; Fleuren, M. ; Voesenek, C.J. ; Leeuwen, J.L. van; Pollux, B.J.A. - \ 2014
Reconstructing changes in 3D body shape during the pregnancy of three species of viviparous fish (Poeciliidae): effects of placentation and superfetation
Fleuren, M. ; Quicazan Rubio, E.M. ; Voesenek, C.J. ; Leeuwen, J.L. van; Pollux, B.J.A. - \ 2014
Viviparity confers a high reproductive burden to females, because they carry their offspring for a long period of time and often undergo a large change in mass and volume. Viviparous organisms have evolved a number of different reproductive adaptations that help reduce the burden during gestation. We recently proposed that placentation and superfetation are two such reproductive adaptations. Placentotrophic fish produce small egg cells with relative low amounts of yolk that are supplied with nutrients over the course of development, resulting in large differences in body volume between the early and last days of gestation. Superfetation, having multiple broods of different developmental stages, reduces the amount of simultaneously present late-stage embryos and thus the volume and mass changes associated with this stage. We illustrate this using three species that differ in the level of post-fertilization maternal provisioning and superfetation: Poeciliopsis gracilis (Matrotrophy Index: 0.7; Superfetation Index: 2), Poeciliopsis turneri (MI: 41; SI: 2) and Phalloptychus januarius (MI: 23, SI: 14). At multiple time points during their pregnancy, females are photographed from 3 orthogonal directions. The multiple images are analysed using semi-automated in-house software, yielding highly accurate three-dimensional body models. Shape parameters derived from the body models are then used to assess changes in the 3D body shape of females during gestation. Ultimately, we are interested in comparing the pregnancy-related changes in 3D body shape between viviparous species that differ in their level of placentation and/or superfetation.
Check title to add to marked list
<< previous | next >>

Show 20 50 100 records per page

 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.