References of "Lagardère, Françoise"
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See detailOntogenic and ecological control of metamorphosis onset in a carapid fish, Carapus homei: Experimental evidence from vertebra and otolith comparisons
Parmentier, Eric ULg; Lecchini, David; Lagardere, Françoise et al

in Journal of Experimental Zoology. Part A, Comparative Experimental Biology (2004), 301A(8), 617-628

In Carapus homei, reef colonisation is associated with a penetration inside a sea cucumber followed by heavy transformations during which the length of the fish is reduced by 60%. By comparing vertebral ... [more ▼]

In Carapus homei, reef colonisation is associated with a penetration inside a sea cucumber followed by heavy transformations during which the length of the fish is reduced by 60%. By comparing vertebral axis to otolith ontogenetic changes, this study aimed (i) to specify the events linked to metamorphosis, and (ii) to establish to what extent these fish have the ability to delay it. Different larvae of C. homei were caught when settling on the reef and kept in different experimental conditions for at least 7 days and up to 21 days: darkness or natural light conditions, presence of sea cucumber or not, and food deprivation or not. Whatever the nutritional condition, a period of darkness seems sufficient to initiate metamorphosis. Twenty-one days in natural light conditions delayed metamorphosis, whereas the whole metamorphosis process is the fastest (15 days) for larvae living in sea cucumbers. Whether the metamorphosis was initiated or not, otoliths were modified with the formation of a transition zone, whose structure varied depending on the experimental conditions. At day 21, larvae maintained in darkness had an otolith transition zone with more increments (around 80), albeit wider than those (more or less 21) of individuals kept under natural lighting. These differences in otolith growth could indicate an increased incorporation rate of released metabolites by metamorphosing larvae. However, the presence of a transition zone in delayed-metamorphosis larvae suggests that these otolith changes record the endogenously-induced onset of metamorphosis, whereas body transformations seem to be modulated by the environmental conditions of settlement. (C) 2004 Wiley-Liss, Inc. [less ▲]

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See detailRelationships between inner ear and sagitta growth during ontogenesis of three Carapini species, and consequences of life-history events on the otolith microstructure
Parmentier, Eric ULg; Lagardère, Françoise; Vandewalle, Pierre ULg

in Marine Biology (2002), 141(3), 491-501

Three species of Carapidae have in common a tenuis larval stage, during which they settle in the lagoon and take refuge in the same species of holothurold. From the juvenile stage, Carapus homei and C ... [more ▼]

Three species of Carapidae have in common a tenuis larval stage, during which they settle in the lagoon and take refuge in the same species of holothurold. From the juvenile stage, Carapus homei and C. boraborensis are commensal, whereas Encheliophis gracilis is parasitic. The aims of this study were to analyse to what extent the ontogenctic changes of the otic capsule affected the shape of the inner ear and how environmental cues, due to the above-mentioned life history and the style, could influence the structure of the sagitta. Sagittal sections revealed a three-dimensional asymmetry with a nucleus close to the proximal surface. Observations of the growth axis of the sagitta suggest it has a morphogenetic impact on the otic cavity. Each sagitta contains three main zones related to the life stages of the fish. Bands and checks were observed in the third zone in C. homei and C. boraborensis, but this pattern was less discernible in E. gracilis. These structural differences in zone 3 could be related to the commensal and parasitic life styles of these fishes. Further studies dealing with otosac features and otolith functions are suggested. [less ▲]

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See detailStudy of the otolith and otic area in Carapidae fishes: eco-morphological implication ?
Parmentier, Eric ULg; Lagardère, Françoise; Diogo, Rui et al

Poster (2001)

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See detailMorpho-anatomy of the otic region in carapid fishes : eco-morphological study of their otoliths
Parmentier, Eric ULg; Vandewalle, Pierre ULg; Lagardère, Françoise

in Journal of Fish Biology (2001), 58

Carapid species are characterized by so-called otophysical structures (sonic muscles, broad first apophyses covering the anterior part of the swimbladder, etc.) The family includes pelagic (Pyramodon and ... [more ▼]

Carapid species are characterized by so-called otophysical structures (sonic muscles, broad first apophyses covering the anterior part of the swimbladder, etc.) The family includes pelagic (Pyramodon and Snyderidia) and benthic (Echiodon) species and ones that are either commensal with (Onuxodon, Carapus) or parasites of (Encheliophis) invertebrates (sea cucumbers, etc). The aim of the present work was to seek possible relationships between the structures of the inner ear (particularly the sagitta) on the one hand and otophysical structures and lifestyles within the Carapidae family. In the eight species studied, the otic cavity is wide, the saccular otosac and its sagitta are particularly developed. The sacculi touch each other on the median line. A comparison of the inner ear structures reveals notably that the species with the most developed sagitta and sacculus are those with the largest parapophyses and have a commensal or parasitic lifestyle. [less ▲]

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