References of "Baras, E"
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See detailSexual dimorphism in two pure cichlid species, Oreochromis niloticus and Sarotherodon melanotheron, and their intergeneric hybrids
Toguyeni, A.; Fauconneau, B.; Mélard, Charles ULg et al

in African Journal of Aquatic Science (2009), 34

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See detailEarly development of the head skeleton in Brycon moorei (Pisces, Ostariophysi, Characidae)
Vandewalle, Pierre ULg; Germeau, G.; Besancenet, P. et al

in Journal of Fish Biology (2005), 66(4), 996-1024

At hatching (15 h post fertilization), Brycon moorei possesses no skeletal structure. Thereafter, development is very rapid. The first oral teeth appear no later than 3 It post-hatching, but they remain ... [more ▼]

At hatching (15 h post fertilization), Brycon moorei possesses no skeletal structure. Thereafter, development is very rapid. The first oral teeth appear no later than 3 It post-hatching, but they remain covered with epithelium until c. 45 h. At 7 h, the trabecular bars and part of the cartilaginous visceral arches are visible and at 15 It, the dentaries and premaxillaries are present. At 25 h, i.e. the onset of piscivory and cannibalism (the yolk sac is only fully resorbed after 36 h), the oral teeth are fully developed, the first pharyngeal teeth are formed, and some head movements already appear synchronized, but the mouth cavity is not completely isolated from the neurocranium by bony structures. Thereafter, no new buccal or pharyngeal bony structure is visible until 45 h, when the maxilla and opercula appear, along with a new type of cannibalistic behaviour. Cartilage resorptions also start at 45 It, but with no concomitant replacement by formation of calcified structures. Later, development gradually becomes similar to that of many previously studied teleosts. The developmental pattern of B. moorei is thus extremely rapid in comparison with other teleosts, i.e. it prioritizes feeding structures that permit the expression of piscivory at a very early age. The uniqueness of this pattern is discussed in relation to ecological constraints on early feeding and fast growth. (c) 2005 The Fisheries Society of the British Isles. [less ▲]

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See detailSize heterogeneity, cannibalism and competition in cultured predatory fish larvae: biotic and abiotic influences
Kestemont, P.; Jourdan, S.; Houbart, M. et al

in Aquaculture (2003), 227(1-4), 333-356

Growth heterogeneity is a central problem in larviculture and especially in predatory species. It can be influenced by a wide range of intrinsic and environmental factors, of which the respective ... [more ▼]

Growth heterogeneity is a central problem in larviculture and especially in predatory species. It can be influenced by a wide range of intrinsic and environmental factors, of which the respective influences are largely unknown. The role of non-interactive (temperature, day length, light intensity, food availability and composition) and interactive factors (stocking density, initial size heterogeneity, hatching time) on growth, survival and size heterogeneity was measured in larvae and post-larvae of the European seabass Dicentrarchus labrax and Eurasian perch Perca fluviatilis. Embryos hatching later than others were found less competitive than those hatching earlier in both species, but to a greater extent in perch. By contrast, the final size heterogeneity in both species was independent from the initial size heterogeneity or recurrent size sorting. High stocking density had a positive effect on perch larvae, no effect on seabass larvae and a negative impact on the post-larvae of both species, owing principally to density-dependent access to food. Day length and light intensity produced contrasting results in larvae and post-larvae. Larvae of both species performed better under bright light and continuous day length. Post-larvae of seabass performed equally well at different light levels but did better under short day lengths, whereas post-larvae of perch were unaffected by day length but performed better under reduced light levels. Increasing food availability resulted in increasing performance of perch larvae, although cannibalism was higher for submaximal than for maintenance rations. The similarity between the two species at the larval stage, and differences at the post-larval stage can be accounted for by the increasing specialisation towards specific environments and niches. Regarding the impact of rearing factors on growth, survival and size heterogeneity, interactive variables impacted essentially on growth and survival, whereas size heterogeneity was chiefly influenced by non-interactive variables, either directly or indirectly via interactive mechanisms such as cannibalism and size-dependent mortality. (C) 2003 Elsevier B.V. All rights reserved. [less ▲]

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See detailEffect of stocking density on the dynamics of cannibalism in sibling larvae of Perca fluviatilis under controlled conditions
Baras, E.; Kestemont, P.; Mélard, Charles ULg

in Aquaculture (2003), 219(1-4), 241-255

The effect of stocking density (10, 31.6 and 100 larvae 1(-1); three replicates per treatment) on the day-by-day dynamics of survival, growth and cannibalism was examined in sibling perch larvae reared ... [more ▼]

The effect of stocking density (10, 31.6 and 100 larvae 1(-1); three replicates per treatment) on the day-by-day dynamics of survival, growth and cannibalism was examined in sibling perch larvae reared from eyed-egg stage in 100-1 cages (16L:8D, 20.0 +/- 0.5 degreesC, O-2 greater than or equal to 6.0 mg 1(-1); feeding in excess with live Artemia nauplii during the photophase) during the first 3 weeks of exogenous feeding. Larvae unable to achieve the transition to exogenous feeding died in between 7 and I I days post-hatch. Later, mortality from causes other than cannibalism never exceeded 1% day(-1). Cannibalism did not start before days 10 - 11 and first consisted in the incomplete ingestion of prey attacked tail first, exclusively. This type of cannibalism never caused losses higher than 2.0% of the initial stock, and ceased after days 16-18. From days 12-14 onwards, differential growth was apparent, and cannibals turned to complete cannibalism of small prey ingested head first, which caused greater losses (28-53% of the stock). Increasing the stocking density did not compromise growth and decreased the overall impact of cannibalism through several complementary mechanisms: (i) a postponed emergence of cannibalism, (ii) a lower proportion of cannibals in the population, and (iii) probably a lower rate of cannibalism per capita as predation was complicated and less directed at high stocking density. (C) 2003 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailOntogenetic variations of thermal optimum for growth, and its implication on thermolabile sex determination in blue tilapia
Baras, E.; Mpo'n'tcha, A.; Driouch, H. et al

in Journal of Fish Biology (2002), 61(3), 645-660

Knowledge of how the optimum temperature for growth (Tdegrees(opt)) varies during ontogeny, and how close it is to the temperatures that induce Phenotypic masculinization is fundamental to the ... [more ▼]

Knowledge of how the optimum temperature for growth (Tdegrees(opt)) varies during ontogeny, and how close it is to the temperatures that induce Phenotypic masculinization is fundamental to the understanding of the evolution of thermolabile sex determinism (TSD) in fishes. In blue tilapia Oreochromis aureus, Tdegrees(opt) is 32.6degrees C at the start of exogenous feeding (10 mg fish) and it decreases by c 1degrees C each time that the fish bode mass increases by an order of magnitude. Temperatures <35degrees C are not sufficient to induce complete phenotypic masculinization. Based on a multiple-regression model (r(2)=0.938) plotting growth against body mass and water temperature. genotypically female tilapia living at high temperatures during the thermosensitive period (21-28 days) and being reversed into phenotypic males should incur an initial growth disadvantage over fish living at Tdegrees(opt) but not over those living at slightly colder temperatures (27-29degrees C). This initial disadvantage would be later compensated for by faster growth because of between-sex growth dimorphism to the detriment of phenotypic females. These arguments suggest that there is no definite pressure against the selection of TSD in blue tilapia and probable other Oreochromis spp. (C) 2002 The Fisheries Society of the British Isles. Published by Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailSibling cannibalism in dorada under experimental conditions. I. Ontogeny, dynamics, bioenergetics of cannibalism and prey size selectivity
Baras, E.; Ndao, E.; Maxi, M. et al

in Journal of Fish Biology (2000), 57

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See detailSibling cannibalism in dorada under experimental conditions. II. Effect of initial size heterogeneity, diet and light regime on early cannibalism
Baras, E.; Maxi, M. Y.; Ndao, J. et al

in Journal of Fish Biology (2000), 57

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See detailPhenotypic sex reversal of blue tilapia under constant and fluctuating thermal regimes, and its adaptive and evolutionary implications
Baras, E.; Prignon, Christian ULg; Gohoungo, G. et al

in Journal of Fish Biology (2000), 192

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See detailThe effect of PIT tags on growth and physiology of age-0 cultured Eurasian perch Perca fluviatilis of variable size
Baras, E.; Malbrouck, C.; Houbart, M. et al

in Aquaculture (2000), 185

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See detailEvaluation of implantation procedures for PIT tagging juvenile Nile tilapia
Baras, E.; Westerloppe, L.; Mélard, Charles ULg et al

in North American Journal of Aquaculture (1999), 61

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See detailFeeding in darkness alleviates density-dependent growth of juvenile vundu catfish Heterobranchus longifilis (Clariidae)
Baras, E.; Tissier, F.; Westerloppe, L. et al

in Aquatic Living Resources (1998), 11

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See detailOccurrence and impact of Heteropolaria (Protozoa: Ciliophora), on intensively cultured perch Perca fluviatilis
Grignard, J. C.; Mélard, Charles ULg; Baras, E. et al

in Annales Zoologici Fennici (1996), 33

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See detailComparison of food conversion by the Pirapatinga Piaractus brachypomus under different times of feeding
Baras, E.; Mélard, Charles ULg; Grignard, J. C. et al

in Progressive Fish-Culturist (1996), 58

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See detailRelationships between growth, cannibalism and survival rate in intensively cultured larvae and alevins of perch (Perca fluviatilis)
Mélard, Charles ULg; Baras, E.; Mary, L. et al

in Annales Zoologici Fennici (1996), 33

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See detailA review of recent developments of behavioural studies in cichlid species.
Poncin, Pascal ULg; Baras, E.

Conference (1994)

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