A β-blocker with a Carazolol base was used by bath, and tested in 0 + sea-bass subjected to stress. In the first experiment, stress was induced by emptying the tank. In the second experiment, the compound was used during an imaginary 24-h transportation, and compared with MS 222. The main modifications noted concern the erythrocytes and the osmotic pressure of the plasma. Compared with fish transported with MS 222 (15 mg/l), the fish subjected to the β-blocker (140 mg/l) had a larger number of red blood cells, in which the haemoglobin concentration (CCMH) was higher and the globular volume smaller. Their osmotic pressure and their chloraemia were lower, which seems to show a higher efficacy of the β-blocker in restricting failures of osmoregulation.

A 1-h temperature increase from 20 to 26°C results in a stress response of the young European sea bass: spleen contraction, an increase in the erythrocytes count, hyperglycaemia, and hyperosmolarity.

Two trials showed that scrubbing the tank walls for 5 min resulted in a change of some blood parameters of the young European sea bass. Half an hour after beginning the scrubbing a significant increase of the following parameters was noted: erythrocytes number, hematocrit, hemoglobinemia, osmotic pressure of plasma, chloremia, natremia, glycemia and, in half of the cases, proteinemia.