References of "Olivier, Damien"
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See detailThe cerato-mandibular ligament: a key functional trait for grazing in damselfishes (Pomacentridae)
Olivier, Damien ULg; Frederich, Bruno ULg; Spanopoulos-Zarco, Milton et al

in Frontiers in Zoology (2014), 11(63), 1-14

Introduction: The success of a taxonomic group can be promoted by a key character that allows the group to interact with its environment in a different way and to potentially occupy new niches. The ... [more ▼]

Introduction: The success of a taxonomic group can be promoted by a key character that allows the group to interact with its environment in a different way and to potentially occupy new niches. The Pomacentridae possess a synapomorphic trait, the cerato-mandibular (c-md) ligament, which joins the hyoid bar to the inner part of the lower jaw. It has previously been shown that this ligament is a key trait in communication in damselfishes because it enables them to slam the oral jaws shut causing teeth collision and sound production. This specific behavior of mouth closing could, however, also be used for other tasks, such as feeding. Many territorial damselfishes are referred to as farmers, due to their ability to manage algal crops on which they feed. This study hypothesizes that the c-md ligament provides an advantage for grazing filamentous algae, and should thus be considered a key trait for farming behavior. Results: The kinematic patterns associated with sound production and biting filamentous algae or attached animal prey are all based on the same mechanism and are associated with a slam of the oral jaws. We observed that transection of the c-md ligaments makes the fish unable to perform such actions. We also counted biting rates on filamentous algae in fish with and without the c-md ligament and observed a drop of more than 80% in the latter. Conclusion: This study shows that the c-md ligament is a key trait both for sound production and for grazing activities in damselfishes. The buccal jaw slam enables the fish to perform accurate strikes on small filamentous algae. This kind of bite probably plays a major role in farming activity and allows grazing damselfishes to occupy distinct niches, possibly increasing their competitive evolutionary success. [less ▲]

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See detailTrait decoupling promotes evolutionary diversification of the trophic and acoustic system of damselfishes
Frederich, Bruno ULg; Olivier, Damien ULg; Litsios, Glenn et al

in Proceedings of the Royal Society B : Biological Sciences (2014)

Trait decoupling, wherein evolutionary release of constraints permits specialization of formerly integrated structures, represents a major conceptual framework for interpreting patterns of organismal ... [more ▼]

Trait decoupling, wherein evolutionary release of constraints permits specialization of formerly integrated structures, represents a major conceptual framework for interpreting patterns of organismal diversity. However, few empirical tests of this hypothesis exist. A central prediction, that the tempo of morphological evolution and ecological diversification should increase following decoupling events, remains inadequately tested. In damselfishes (Pomacentridae), a ceratomandibular ligament links the hyoid bar and lower jaws, coupling two main morphofunctional units directly involved in both feeding and sound production. Here, we test the decoupling hypothesis by examining the evolutionary consequences of the loss of the ceratomandibular ligament in multiple damselfish lineages. As predicted, we find that rates of morphological evolution of trophic structures increased following the loss of the ligament. However, this increase in evolutionary rate is not associated with an increase in trophic breadth, but rather with morphofunctional specialization for the capture of zooplanktonic prey. Lineages lacking the ceratomandibular ligament also shows different acoustic signals (i.e. higher variation of pulse periods) from others, resulting in an increase of the acoustic diversity across the family. Our results support the idea that trait decoupling can increase morphological and behavioral diversity through increased specialization rather than the generation of novel ecotypes. [less ▲]

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See detailA ligament influences the diversification of damselfishes (Pomacentridae)
Frederich, Bruno ULg; Olivier, Damien ULg; Litsios, Glenn et al

Conference (2013, June)

The Pomacentridae (damselfishes) is one of the most successful families of reef-associated fishes (386 species). In 1981, Stiassny described a synapomorphic trait of the Pomacentridae: the cerato ... [more ▼]

The Pomacentridae (damselfishes) is one of the most successful families of reef-associated fishes (386 species). In 1981, Stiassny described a synapomorphic trait of the Pomacentridae: the cerato-mandibular ligament (CML) joining the hyoid bar (ceratohyal) to the internal part of the mandible (coronoid process of the articulo-angular). Here, we highlight that this ligament is lacking in at least 18 damselfish species from different subclades (i.e. Chrominae, Abudefdufinae and Pomacentrinae) and we explore the impact of its disappearance on lineage, morphological and ecological diversification through their evolutionary history. Using a time-calibrated phylogeny including 208 species, we found no support for different rates of lineage diversification between species that lack the CML and the others. Yet, the CML clearly governs a part of the morphological diversity in damselfishes. Indeed, the body and mandible shapes differ significantly between species without CML and the others. Evolutionary modeling of some phenotypic traits (i.e. body and mandible shape) mainly supports models with two rates of morphological diversification across the time-tree with the species without CML having a higher rate of morphological diversification than the others. Mapping the diet of all studied species illustrates that damselfishes lacking CML are highly zooplanktivorous species. Their shapes suggest they feed on planktonic copepods with a higher contribution of ram-feeding (i.e. predator movement towards prey) in comparison with the other planktivorous damselfishes. Finally, the CML could have promoted easy shifts among the three main trophic guilds in damselfishes (i.e. grazers, zooplanktivorous and omnivorous) during evolution but the disappearance of the CML allowed a functional specialization linked to prey-capture strategies. These results support the primary role of the CML in the evolution and diversification of pomacentrids. [less ▲]

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See detailKinematic analysis of swimming ontogeny in seabass (Dicentrarchus labrax).
Olivier, Damien ULg; Vandewalle, Nicolas ULg; Parmentier, Eric ULg et al

in Belgian Journal of Zoology (2013)

Swimming has been investigated in multiple species, but few studies consider the establishment of swimming through ontogeny. This study describes the establishment of cyclical swimming in Dicentrachus ... [more ▼]

Swimming has been investigated in multiple species, but few studies consider the establishment of swimming through ontogeny. This study describes the establishment of cyclical swimming in Dicentrachus labrax, a marine fish from cold, temperate waters. The data were compared with results from previous studies on two subtropical freshwater catfish species (Clarias gariepinus and Corydoras aeneus). The three species have different modes of locomotion during their adult stage (anguilliform, subacarangiform and carangiform). The swimming of Dicentrarchus labrax was recorded with a high-speed video camera (500 fps) from 0 to 288 hours and from 960 to 2496 hours post-hatching. Three indices, i.e. coefficient of determination (r²), coefficient of variation (CV), and Strouhal number (St), were used to investigate the establishment and efficiency of swimming. Important differences in the timing of swimming establishment were observed between the seabass and the two catfish species. The two catfish species display a sine-shape swimming mode immediately or soon after hatching, and the efficiency of movement substantially improves during the first days of life. For seabass, however, establishment of swimming is slower during the same developmental period. These differences may be related to a faster developmental rate in the catfishes that allows them to swim rapidly in an intermediate regime flow and to develop the required morphology to establish efficient movements earlier. [less ▲]

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See detailOntogeny of swimming movement in bronze corydoras (Corydoras aeneus)
Mauguit, Quentin; Olivier, Damien ULg; Vandewalle, Nicolas ULg et al

in Canadian Journal of Zoology (2010), 88(4), 378-389

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See detailSwimming ontogeny in Dicentrarchus labrax
Olivier, Damien ULg; Parmentier, Eric ULg

Poster (2009, October)

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See detailEtude de l'organisation des mouvements de nage au cours de l'ontogenèse chez Dicentrarchus labrax (Teleostei, Serranidae): Approche quantitative
Olivier, Damien ULg

Master's dissertation (2009)

The swimming movements of Dicentrarchus labrax larvae were recorded with a high-speed video camera (500 fps) from 0 to 288 hours post-hatching. Three indices were used to investigate the establishment ... [more ▼]

The swimming movements of Dicentrarchus labrax larvae were recorded with a high-speed video camera (500 fps) from 0 to 288 hours post-hatching. Three indices were used to investigate the establishment (coefficient of determination r²; coefficient of variation of r²) and the efficiency (Strouhal number) of the swimming movements. Movements of juveniles (960 to 2496 hours post-hatching) were also recorded to make comparisons with larvae. At hatching, larvae were unable to swim with well-sinusoidal movements. During growth, there was an improvement in the sinusoidal path of the swimming movement until the size of 5.2 mm TL where all larvae performed sinusoidal movements. The swimming speed had a strong effect on indices; all larvae with a burst swim performed sinusoidal movement as soon as at a size of 3.2 mm TL. The swimming efficiency improved with the Reynolds number and so with the size and the swimming speed. The maximal lateral amplitude of the various body parts decreased progressively during growth. At last, a switch from anguilliform to subcarangiform swimming mode occurred during the transition to the juvenile stage. [less ▲]

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