Haematological changes in the blood of cultured Clarias gariepinus stored at room and refrigerator temperatures

Abstract

This study investigated the artifactual changes in the haematological values of Clarias gariepinus blood stored at room (32^oC) and refrigerator (4^oC) temperatures. Blood samples were collected from 12 apparently healthy fish weighing between 0.8 and 1kg. Samples were divided into two parts immediately after collection and baseline haematological values determined. Haematological determinations were thereafter carried out at 6 hourly intervals up to the 36th hour and then at the 48th hour. Results showed significant reduction (p<0.05) in PCV and RBC values at the 48th hour from the baseline value at room temperature and no significant variation (p>0.05) at the refrigerator temperature. There were significant increases (p<0.05) in the MCV and MCHC values from the baseline values at the 48th hour and MCH value at 36th hour at room temperature while no significant variations (p>0.05) were observed at refrigerator temperature. There were significant reductions (p<0.05) in the WBC count at the 36th and 48th hours when compared with the baseline value at both room and refrigerator temperatures while HBC values did not vary significantly (p>0.05) in both temperatures all through the duration of the study. Reliable RBC count can be obtained up to the 12th hour; WBC and MCH up to the 30th hour; PCV, MCV and MCHC up to the 36th hour and HBC up to the 48th hour at room temperature while at refrigerator temperature, reliable values can be obtained up to the 48th hour in all the parameters determined except WBC count that can be obtained up to the 30th hour of storage.

Keywords: Clarias gariepinus, Blood, Artifactual changes, Haematology, Duration of storage, Storage temperature