Hematological and plasma biochemical parameters in a wild population of Naja naja (Linnaeus, 1758) in Sri Lanka

 

Duminda S. B. Dissanayake¹, Lasanthika D. Thewarage¹, Rathnayake M. P. Manel Rathnayake², Senanayake A. M. Kularatne³, Jamburagoda G. Shirani Ranasinghe⁴, Rajapakse P. V. Jayantha Rajapakse¹

 

1 Department of Veterinary Pathobiology, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, Peradeniya, Sri Lanka.

2 Department of Pathology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka.

3 Department of Medicine, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka.

4 Department of Biochemistry, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka.

 

ABSTRACT

Background

Hematological studies of any animal species comprise an important diagnostic method in veterinary medicine and an essential tool for the conservation of species. In Sri Lanka, this essential technique has been ignored in studies of many species including reptiles. The aim of the present work was to establish a reference range of hematological values and morphological characterization of wild spectacled cobras (Naja naja) in Sri Lanka in order to provide a diagnostic tool in the assessment of health condition in reptiles and to diagnose diseases in wild populations.

 

Methods

Blood samples were collected from the ventral caudal vein of 30 wild-caught Naja naja (18 males and 12 females). Hematological analyses were performed using manual standard methods.

 

Results

Several hematological parameters were examined and their mean values were: red blood cell count 0.581 ± 0.035 × 10⁶/μL in males; 0.4950 ± 0.0408 × 10⁶/μL in females; white blood cell count 12.45 ± 1.32 × 10³/μL in males; 11.98 ± 1.62 × 10³/μL in females; PCV (%) in males was 30.11 ± 1.93 and in females was 23.41 ± 1.67; hemoglobin (g/dL) was 7.6 ± 0.89 in males and 6.62 ± 1.49 in females; plasma protein (g/dL) was 5.11 ± 0.75 in males and 3.25 ± 0.74 in females; whereas cholesterol (mg/mL) was 4.09 ± 0.12 in males and 3.78 ± 0.42 in females. There were no significant differences in hematological parameters between the two genders except for erythrocyte count, thrombocyte count, hematocrit, hemoglobin, plasma protein, percentage of azurophil and heterophil. Intracellular parasites were not found in any of the studied specimens.

 

Conclusion

Hematological and plasma biochemical parameters indicated a difference between geographically isolated populations and some values were significantly different between the two genders. These hematological results provide a reference range for Sri Lankan population of adult Naja naja.

 

Key words: Hematology; Blood cells; Plasma biochemistry; Naja naja.

 

Funding

This work was supported by a grant from the Ministry of Science, Technology and Research –MoSTR (MTR/TRD/AGR/3/1/7) of Sri Lanka.

 

Received: July 1, 2016.

Revised: January 27, 2017.

Accepted: February 13, 2017.

 

Correspondence: jayanthar@pdn.ac.lk

 

Authors’ contributions

DSBD, RPVJ, SAMK and JGSR designed the study. DSBD and RPVJ captured the snakes from different geographical areas in Sri Lanka and collected their blood. DSBD, LDT and RMPMR carried out the laboratory work. All authors participated analysis, interpretation of data and in writing of the manuscript. All authors read and approved the final manuscript.

 

Competing interests

The authors declare that they have no competing interests.

 

Ethics approval and consent to participate

The permission for collecting snakes from different geographical locations was granted by the Department of Wildlife Conservation (WL/3/2/13/14).