engleski

Seasonal variations of some blood parameters in farmed sea bass (Dicentrarchus labrax L.)

Background and purposes: Seasonal variations of 13 haematological and biochemical parameters were examined in sea bass (Dicentrarchus labrax L.) in relation to growth, sexual maturation and some physicochemical parameters of the marine environment. Material and methods: Fifteen specimens of two-year-old sea bass, farmed in the Centre for mariculture MARIMIRNA in the Limski kanal were monthly sampled from April to December. For every fish separately, beyond the standard morphological values, blood was taken by cardiac puncture and the basic haematological and biochemical parameters were measured by standardized methods. Hydrographic data were checked using standard oceanographic methods. Results and conclusion: Our study confirms that most of the haematological and biochemical monthly values fluctuated during the seasonal cycle. In general haematological parameters as red blood cells and haematocrit were the highest in September, while haemoglobin was the highest in May. Total plasma proteins, lipids, cholesterol and triglycerides also exhibited high fluctuations throughout the year, with maximal values in September and the lowest in December, whereas glucose was the most constant parameter. The correlation analysis does not display significant correlation between any of the nine hydrographic environmental factors and haematological data. Only total protein and albumin strongly correlate with temperature, and total lipids and cholesterol with nitrate in sea water, but we were not able to find any rational explanation. The obtained results suggest that the seasonal variation of haematological and biochemical parameters are not directly affected by physical and chemical fluctuation of the environmental water, but they are particularly related to sexual maturation and reproductive intervals as well as to feeding behaviour.

blood; haematological parameters; biochemical parameters; hydrographic data; sea bass; Dicentrarchus labrax L.

nije evidentirano