Incidence de la salinite sur les equilibres de distribution hydrique et ioniques et sur le metabolisme respiratoire dans le muscle blanc, le muscle rouge et la branchie chez le muge Chelon labrosus

Oxygen consumption, water, K super(+) and Na super(+) contents were measured in white muscle, red muscle and gill epithelium in the mullet Chelon labrosus) in relation with the duration of fresh water or sea water (1500mOsm) adaptation. The unit respiratory activities in gill and red muscle where respectively 5 and 3 timesmore elevated than in white muscle. The pericellular K super(+)/Na super(+) ratio of the 3 tissues decreased with the fresh water adaptation duration. In the gill, the intracellular K super(+)/Na super(+) ratio was stable while the parameter decreased strongly in the white muscle. The results are discussed in relation to energetic cost of homocellular regulation and homoepithelial regulation.