Ralph E. Werner, VMD
Abstract
The diamondback terrapin (Malaclemys terrapin) is an inhabitant of the coastal marshlands of the eastern and southern United States. This unique turtle spends its life in tidewater creeks and ponds. Pressure from hunting, coastal construction, vehicle traffic, oil spills, and predation has prompted conservation efforts to protect the diamondback. Health assessment is a vital aspect of species management and conservation but can be quite difficult if reference blood values are not available.
Prior to collecting blood samples, a small study was done to determine the optimal collection site in the diamondback.7 The femoral vein proved to be the best vessel for obtaining blood that was not diluted by lymph, so it was used throughout this study. Sampling of 103 terrapins was performed in two locations—Stone Harbor, NJ and Wellfleet, MA. The complete blood count and serum biochemistry panel was performed at Antech Diagnostics (Lake Success, NY). The white blood cell count (WBC) was estimated from a peripheral blood smear, and biochemical testing was performed using an Olympus Automated Chemistry Analyzer. Hemoglobin concentration was determined by the author.
Hematocrit, hemoglobin, and white blood cell counts are shown in Table 1. They are similar to those published for other turtle species.4-6 Serum chemistries (Table 2), on the other hand, showed quite a lot of variation and were often dissimilar to values reported for other species.2-6 There were significant differences (p<0.05) between males and females for WBC counts, calcium, phosphorous, chloride, total protein (TP), and albumin (Table 3).
Table 1. RBC and WBC values for Malaclemys terrapin
|
|
Mean
|
SD
|
Range
|
|
Hematocrit (%)
|
31.8
|
7.6
|
15–55
|
|
Hemoglobin (g/dl)
|
9.6
|
1.1
|
7–11.7
|
|
WBC (103/µl)
|
11.3
|
4.5
|
3.5–28
|
|
Heterophils (%)
|
74.6
|
13.4
|
29–91
|
|
Lymphocytes (%)
|
17.7
|
12.6
|
4–63
|
|
Monocytes (%)
|
2.3
|
3.0
|
0–16
|
|
Eosinophils (%)
|
1.1
|
1.9
|
0–7
|
|
Basophils (%)
|
1.6
|
2.1
|
0–14
|
|
Azurophils (%)
|
3.8
|
3.5
|
0–14
|
Table 2. Serum chemistry values for Malaclemys terrapin
|
|
Mean
|
SD
|
Range
|
|
Glucose (mg/dl)
|
100.9
|
69.0
|
10–267
|
|
SUN (mg/dl)
|
104.7
|
54.0
|
27–258
|
|
Uric acid (mg/dl)
|
1.3
|
0.9
|
0.3–5.3
|
|
TP (g/dl)
|
4.1
|
0.8
|
1.8–5.7
|
|
Albumin (g/dl)
|
1.3
|
0.3
|
0.4–2
|
|
Globulin (g/dl)
|
2.8
|
0.6
|
1.4–3.9
|
|
Calcium (mg/dl)
|
13.0
|
5.0
|
6.6–30
|
|
Phosphorus (mg/dl)
|
5.3
|
1.7
|
2.8–11.1
|
|
Sodium (mEq/L)
|
148.7
|
11.0
|
120–174
|
|
Potassium (mEq/L)
|
4.9
|
1.0
|
3.4–7.5
|
|
Chloride (mEq/L)
|
106.9
|
9.7
|
86–123
|
|
AST (U/L)
|
218.1
|
130.1
|
5–681
|
|
CPK (U/L)
|
4194.1
|
3849.4
|
261–21570
|
Table 3. Blood and chemistry values significantly different between male and female Malaclemys terrapin (p<0.05)
|
|
Males
|
Females
|
|
Mean
|
SD
|
Mean
|
SD
|
|
WBC (103/µl)
|
13.9
|
4.8
|
10.6
|
3.9
|
|
Calcium (mg/dl)
|
9.2
|
1.3
|
13.0
|
5.1
|
|
Phosphorus (mg/dl)
|
4.1
|
0.7
|
5.5
|
1.7
|
|
Chloride (mEq/L)
|
99.7
|
11.2
|
108.0
|
9.1
|
|
Total protein (g/dl)
|
3.6
|
1.1
|
4.2
|
0.7
|
|
Albumin (g/dl)
|
1.0
|
0.3
|
1.3
|
0.3
|
Many of the biochemical parameters, including glucose, uric acid, AST, and CPK showed wide variability among individuals. Such variability has also been noted for a number of other chelonian species, and it is possible that these parameters lack sensitivity and specificity for diagnosis of disease in this group of reptiles.1-6 Further studies are needed to investigate the correlation of changes in serum chemistry values, systemic illness, and organ-specific pathology of chelonians. The higher total protein elevation in females was probably due to an increase in albumin and vitellin (a plasma protein that is high during egg laying). The higher calcium and phosphorous results for females were also likely due to the process of ovulation. The chloride increase in females may have been the result of dehydration as they migrated on land to nesting sites.
Blood testing of additional diamondback terrapin populations and obviously ill individuals will be necessary to provide more information on the diagnostic value of the various parameters examined in this study.
Literature Cited
1. Chandavar, V.R., and P.R. Naik. 2004. Variation in plasma glucose and pancreatic β cells in the turtle, L punctata (order: Chelonia; family: Trionychidae). Acta Zool. 85(2):113–118.
2. Duncan, R.J., K.W. Prasse, and E.A. Mahaffey. 1994. Veterinary Laboratory Medicine. 3rd ed. Iowa State University Press, Ames, Iowa. 300 pp.
3. Frye, F.L. 1991. Reptile Care. T.F.H. Publishing, Neptune City, NJ. 637 pp.
4. Fudge, A.M. (ed.) 2000. Laboratory Medicine Avian and Exotic Pets. W.B. Saunders Co., Philadelphia, PA. 486 pp.
5. McArthur, S., R. Wilkinson, and J. Meyer. 2004. Medicine and Surgery of Tortoises and Turtles. Blackwell Publishing, Oxford, UK. 579 pp.
6. Mader, D.R. (ed.). 1996. Reptile Medicine and Surgery. W.B. Saunders Co. Philadelphia, PA. 512 pp.
7. Werner, R.E., and L.C. Lindley. 2005. The effect of lymph dilution on blood samples collected from the diamondback terrapin (Malaclemys terrapin). J. Herp. Med. Surg. 15(4):26–27.