HAEMATOLOGICAL RESPONSE OF ACIPENSER STELLATUS JUVENILES IN COLD SHOCK STRESS

Iulia Grecu, Angelica Docan, Lorena Dediu, Alina Antache, Mirela Creţu, Marilena Maereanu

Abstract
   During the intensive growth of the sturgeons, different stressful factors may occur which could act isolated or in association, influencing their physiological state. In these conditions, the organism tries to cope through a series of biochemical and physiological changes as a result of the activation, in cascade, of some mechanisms of the neuroendocrine response to these stressors. This paper presents the results of the haematological investigations in a controlled experiment that followed the effect of the cold shock stress of water temperature, in the range 12.8 °C ÷ 7 °C (initially, after 1 hour, respectively after 3 hours) on the physiology of the Acipenser stellatus species (stellate sturgeon), a very valuable species for sturgeon farming in Romania. This experiment was part of a series of experiments applied to intensive sturgeon breeding with the aim of selecting specific molecular and biochemical markers (gene and protein expressions) to allow the analysis of the response mechanisms to stress factors in aquaculture. Haematological indices and erythrocyte constants were determined using standard methods for veterinary haematology and the data obtained were statistically processed. The determined values of the haematological parameters ranged near the lower limit of the optimum interval for Acipenseridae. In the context of our study, although there was a constant increasing tendency of haematocrit (Ht) values with the raise of the exposure to cold (14.46% - initially, 16.39% - after 1 hour, respectively 17.51% - after 3 hours), in parallel with a less uniform reaction of the other haematological parameters, the statistical analysis did not reveal significant differences between the three experimental groups. The obtained data show the evolution of the haematological profile of the stellate sturgeon and it is useful in completing the database with reference values for research in the field of sturgeon culture.

Key words: Acipenser stellatus, cold shock, acute stress, haematology