67 research outputs found

    Biology and culture of the clown loach Chromobotia macracanthus (Cypriniformes, Cobitidae) : 1- Hormonal induced breeding, unusual latency response and egg production in two populations from Sumatra and Borneo Islands

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    The clown loach Chromobotia macracanthus, endemic to Indonesia, is a major species on the international market of ornamental freshwater fish. In order to satisfy an increasing demand with a sustainable alternative to the massive capture of wild juveniles, research has been dedicated to the artificial propagation and domestication of this species. The present study, the first of a series, focused on favourable maintenance conditions for broodfish sexual maturation, criteria for identification of ripe fish, efficiency of hormone-induced breeding treatments, predictability of their latency response, and on the comparison of reproductive performances of fish from populations of Sumatra and Borneo Islands (in total, 112 females of 46 to 404 g body weight). When reared in fully controlled conditions in large water recirculation systems, broodfish originating from Sumatra had reproductive performances similar to or slightly higher than those maturing in the wild (ovulation rate of 93% vs. 82%, relative fecundity of 109 277 vs. 103 550 ova kg(-1) and fertilization rate of 73% vs. 61%, respectively). In the same rearing conditions, captive females from Borneo (n = 22) showed lower ovulation rate (77%), relative fecundity (76 262 ova kg(-1)) and fertilization rate (50%) than those originating from Sumatra (n = 28). By contrast, the mean individual weight of ova (around 0.8 mg) was independent from the origin or maintenance conditions of females. An initial modal follicle diameter >= 1.02 mm generally led to high ovulation success (>80%) after hormonal treatment and is recommended as the main criterion for selecting female broodfish. Two hormonal treatments for inducing oocyte maturation and ovulation (T1: two successive injections of Ovaprim at a 6 h-interval; T2: one injection of human chorionic gonadotropin (hCG)-and one of Ovaprim 24 h later), produced similar results in terms of ovulation rate, quantity and quality of ova collected. With both treatments, the latency decreased with increasing water temperature, then increased again at temperatures >28-29 degrees C. To our knowledge, such U-shaped relationship between the latency response and temperature has never been documented in teleost fishes

    Interviewing parents of children in care: perspectives, discourse and accountability

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    The ‘parental perspective’ in child care work is a matter of concern and is actively solicited by practitioners, managers, policymakers and researchers for differing reasons. This paper argues that the search for such a stable “parental perspective” should be abandoned and suggest that research should embrace a social constructionist turn by concentrating on how parents' views are negotiated conversationally in discourse. Using data drawn from research interviews with parents of children in care and employing conversation and discourse analytic methods, the paper demonstrates how there are critical issues of accountability, blame, and testing at stake in the interview encounter, as interviewer and interviewee jointly produce a moral version of the client, the institution, the case and its attributes. The implications of this argument are delineated
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