Sampling procedures are commonly carried out in both laboratories and farms in order to collect samples from animals under experimentation or rearing conditions. In the laboratory, these procedures are necessary to analyse the effects of different treatments (i.e., hormonal, environmental or genetic cues among others) on fish performance under investigation. Like other scientific areas of knowledge, the reproduction area is vast and complex. In particular, the study of those factors involved in the activation of the brain-pituitary-gonad (BPG) axis is crucial for a better understanding of some biological processes related to the estimation of male and female reproductive success in fish. Accordingly, a general overview about practical considerations of how to proceed in a sampling and slaughter procedure to study reproductive aspects of this axis is described in this session. It should be noted that the equipments and protocols available in the laboratory for each species are a key issue to be considered before samples are collected. On the other hand, according to the objectives in each experiment, variations in the way to proceed in sampling and slaughter procedures may occur. A conventional procedure for sample and data collection is described in this Protocol including blood and plasma collection, dissection and tissue collection and estimation of different body indexes in the sea bass.

En laboratoire, les procédures d'échantillonnage sont fréquentes et nécessaires pour l'analyse des effets de différents traitements (hormonaux, environnementaux, génétiques...) sur les performances des poissons. Dans le domaine de la reproduction en particulier, l'étude des facteurs impliqués dans l'activation de l'axe cerveau-hypophyse-gonades (BPG) est primordiale pour une meilleure compréhension de certains processus biologiques de la reproduction des poissons. Cette section fournit, sur un plan pratique, une vue d'ensemble sur la manière de mener une procédure d'échantillonnage, d'abattage et de prélèvements des animaux étudiés.