Risks to bees from dusts emitted at sowing of coated seeds: concerns, risk assessment and risk management

contribution to session V Honey bee poisoning incidents and monitoring scheme

A shortcut method for sexing juvenile European sea bass, Dicentrarchus labrax L.

The objective of this study was to develop a rapid and effective method of sexing juvenile sea bass with minimum labour and material.To this end, the gonad squash mount technique was applied along with macroscopic techniques for sexing a large number of experimental fish at the age of 215-275 days post fertilization (p.f.). At this age, 90% of the 3894 fish could be unambiguously sexed by macroscopic examination of their gonads, whereas the remaining proportion was identified using squash mount preparations (10%). The accuracy of the observations was measured up to classical histology procedures. Undifferentiated gonads accounted for 0.1% of the total population only.The application of the squashmount technique holds out the prospect of considerable improvement in the efficiency and rapidity of current sexing techniques in sea bass

Technical and Environmental Performances of Wood Combustion in Domestic Turbo Boilers: Influence of Operating Parameters

International audienc

Modification of population sex ratios by domestication and artificial selection in the European sea bass (Dicentrarchus labrax L.)

absen

Effects of lindane exposure on rainbow-trout (oncorhynchus-mykiss) immunity .III. Effect on nonspecific immunity and b-lymphocyte functions

Ecotox. Environ. Safe. ISI Document Delivery No.: NL882 Times Cited: 27 Cited Reference Count: 27 Dunier, m siwicki, ak scholtens, j molin, sd vergnet, c studnicka, m Academic press inc jnl-comp subscriptions San diegoInternational audienceThe effect of the organochlorine insecticide lindane (gamma-hexachlorocyclohexane) was examined on some major immune functions of rainbow trout (Oncorhynchus mykiss) on the chemiluminescent response of pronephric cells (PMA-induced) in phagocytosis, on the proliferation of lymphocytes with B and T mitogens, and on the number of B lymphocytes analyzed by cytofluorometry. Two different methods of exposure were tried via food (first protocol) and via a single intraperitoneal injection (second protocol). After the oral contamination at a daily body dose of 1 mg/kg for 30 days, a decreased chemiluminescent response was observed which persisted for two more weeks and disappeared over 1.5 months. No effect was observed on lymphocyte proliferation and on the number of circulating B lymphocytes. In the second protocol lindane was administered intraperitoneally at 10, 50, or 100 mg/kg body wt. After 45 days the lymphocyte proliferation of B cells was depressed but not the T cell one. The B cells number in head kidney as measured by cytofluorometry was not significantly modified. Some nonspecific immunity parameters in sera were significantly modified. (C) 1994 Academic Press, Inc

Can we obtain monosex sea bass populations through selective breeding?

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Quantitative genetic variation for post-stress cortisol and swimming performance in growth-selected and control populations of European sea bass (Dicentrarchus labrax)

Sea bass is a major species in Mediterranean aquaculture, and is now being subject to selective breeding programmes for faster growth. In terrestrial species, it was demonstrated that fast growth may be linked to a correlated degradation of fitness traits. In this experiment, we evaluated 600 young sea bass from a factorial mating of 76 sires and 13 dams. The sires were from four genetic groups, wild (W), domesticated (D), and selected for growth (2 groups, M and P). The 600 offspring were submitted to two acute confinement stress challenges at 6 weeks intervals, and plasma cortisol at one hour post stress was measured. The same fish were also submitted to two swimming challenges at a 5 days interval, where the maximum sustained swimming speed (Umax) of each fish was evaluated. Parentage was assessed by genotyping of 12 microsatellites. 554 fish had both valid parentage and phenotypes. Cortisol had a low repeatability (r = 0.30 between the two successive measurements) while repeatability was moderate for Umax (r = 0.62). However, genetic correlations between successive measurements were very high (> 0.96) for both traits, indicating that successive measurements were related to the same trait. Heritability was moderate for mean post-stress cortisol (h2 = 0.34 ± 0.09) and Umax (h2 = 0.48 ± 0.08). When Umax was expressed in m.s− 1, it was negatively correlated to cortisol (rA = − 0.48 ± 0.08) and weakly correlated to body weight (rA = 0.12 ± 0.16), but figures changed when it was expressed in Body Lengths.s− 1 (h2 = 0.55 ± 0.08, rA = − 0.10 ± 0.19 with cortisol and rA = − 0.64 ± 0.07 with body weight, respectively). Cortisol was moderately negatively correlated with body weight (rA = − 0.36 ± 0.18). The four lines did not differ for cortisol or Umax, but when Umax was expressed in BL.s− 1 it tended to be lower in the two selected lines — which were also significantly larger. However, this is likely due to a phenotypic decrease of relative Umax with increasing body size. We conclude that selection for growth and/or domestication should not impact maximum sustained swimming speed in the European sea bass, but may tend to favour animals with low cortisol responsiveness. These traits could be used to orientate functional capabilities other than productivity in sea bass.Statement of relevance: We estimate heritability of cortisol stress response and (for the first time) in European sea bass, as well as their correlations with growth. We show moderate correlations, and no correlated response to selection for growth. We also provide methods to evaluate these traits on large number of fishes. This can be useful to monitor and design breeding programmes