1. National Elite Foundation – Tehran – Iran ; marinebiology1@gmail.com
Application of Fish Blood as Ecological Indicator of Undesirable Materials
Aliakbar Hedayati*, Alireza Safahieh, Ahmad Savari and Jasem Ghofle Marammazi
National Elite Foundation – Tehran – Iran ;
Methods
Determinations of the number of CBC tests were performed immediately on fresh blood.
Numbers of Blood leukocytes (Lk count 104 cells ml_1) was performed by diluting heparinized blood with Giemsa stain at 1:30 dilution and cells were counted using a hemocytometer_Neubauer under the light microscope (Stevens, 1997).
The leukocyte differential count was made in peripheral blood smears stained by Merck Giemsa (Beutler et al., 2001). Lymphocyte numbers were determined by direct counting under the microscope using a Neubauer chamber.
Hematocrit readings were performed with the aid of a microhematocrit reader.
Hemoglobin levels (Hb mg/100) were determined colorimetrically by measuring the formation of cyanomethemoglobin according to Van Kampen and Zijlstra (1961) and (Lee et al., 1998).
Mean corpuscular hemoglobin concentration (MCHC) were calculated from RBC, Ht, and Hb according to Lee et al. (1998) as MCHC(mg l-1) = Hb(mgdl-1) / Ht(ratio).
Serum total protein levels were determined by the method of Lowry et al. (1951) at 546 nm and 37C. The quantitative determination of serum glucose was carried out by the glucose oxidase method according to Trinder (1969).
Introduction
The measurement of biochemical and physiological parameters is a diagnostic tool commonly used in aquatic toxicology and biomonitoring. Hematological parameters are more often used when clinical diagnoses of fish physiology are used to determine sub chronic concentrations of pollutants (Abdel-Tawwab et al. 2007). Fish blood is sensitive to pollution-induced stress and changes in the hematological and metabolic parameters can be used as toxicity indicators of the toxicant (Sancho et al. 2000). The objectives of current study were to determine the both in vivo and in vitro effects of mercuric chloride (HgCl2) on hematological and immunological features yellowfin sea bream to aim bioindicator of mercury pollution.
Result and Discussion
All in vitro activities exhibited significant analysis of variance (P<0.05), but the statistical analysis did not reveal any significant difference (p>0.05) between control groups and MCHC and differential monocyte.
In vitro result declared significance increase of Hb, Ht and differential monocyte within higher considerable values than those of the control group, beside significance decrease of leukocyte count, differential lymphocyte and eosinophyle (P>0.05) with lower considerable values than those of the control group.
Values recorded for activity of total protein show high significance depletion (P<0.001) with mercury exposed. Although glucose was increase in different treatment, but there was not find significant variation (P<0.05).
Curve estimation regressions data were used to determine the relationship between mercury concentration and Hb, Ht, MCHC, Leucosyte, Lymphocyte, Monocyte, Neutrophil, Eosinophils, Protein and Glucose activity. Only the Ht and monocyte and MCHC levels had not statistically significant and other parameter show significant linear regression (P<0.05) with mercury.
Results of the present investigation indicated that the sub- acute mercury concentrations tested, which are closed to those used in agriculture purposes, may cause several changes in the metabolic and hematological parameters of the studied fish.
Fig 1. Regressions model (Y = a ± bX) of Hb, Leucosyte, Lymphocyte, Neutrophil and Eosinophils of the yellowfin sea bream during in vitro exposed to different concentration of mercury chloride.
Conclusion
The major findings of this study are that the sub- acute and chronic mercury concentrations tested may cause several changes in the hematological and immunological parameters of the studied fish and we can use these changes as biomarkers of mercury detection. In conclusion, estimation of hematological biomarkers in fish, as in the present study, could provide a useful indicator of pollution of water bodies
Acknowledgments
The authors are thankful to the Director and Staff at the Mariculture Research Station, Mahshahr, Iran for providing necessary facilities for the experiment and the University of Marine Science and Technology, Khoramshahr, Iran, for support during the tenure of this project. We would like to express our special thanks to Dr. Movahedinia for assistance during the trials.
References
[1] Abdel-Tawwab, M., Mousa, M.A.A., Ahmad, M.H., Sakr, S.F., The use of calcium pre-exposure as a protective agent against environmental copper toxicity for juvenile Nile tilapia, Oreochromis niloticus (L.). Aquaculture 264 (1-4), 236–246.
[2] Sancho, E., Cero´ n, J.J., Ferrando, M.D., Cholinesterase activity and hematological parameters as biomarkers of sublethal molinate exposure in Anguilla anguilla. Ecotoxicol. Environ. Safe. 46, 81–86