North Carolina State University, College of Veterinary Medicine, Raleigh, NC, USA
Abstract
Although blue crabs (Callinectes sapidus) are a commercially important and valuable species throughout the east coast of North America, very little is known about hemolymph biochemistry values in market populations.1 Available data are dated but do establish some baseline reference range values for wild populations.2,3,4
Hemolymph samples for chemistry analysis were obtained from 20 live female blue crabs acquired from a seafood market in Raleigh, NC. Approximately 1.5mL of hemolymph was obtained via cardiocentesis using a 22 g. needle and syringe, then immediately centrifuged. The serum was sent to the Animal Health Diagnostic Center (Cornell University College of Veterinary Medicine, P.O. Box 5786, Ithaca, NY 14853) for analysis.
Hemolymph averages and standard deviations were calculated for glucose, chloride, sodium, potassium, calcium, uric acid, phosphate, aspartate aminotransferase, glutamate dehydrogenase, creatinine kinase, bile acids, lipemia, and total protein. The measured values for total protein (6.36 ± 1.59 g/dL) and chloride (308.25 ± 21.35 mEq/L) appear to be consistent with the values documented by Lynch and Webb, 1973 and Lynch et al., 1973, respectively, over the course of June, July, and August (total protein: 5.59 ± 0.35, 7.0 ± 0.62, 4.6 ± 0.53 g/dL and chloride: 368 ± 3, 340 ± 8, 300 ± 10 mEq/L).2,3 The measured glucose value (37.2 ± 11.01 mg/dL), however, is less consistent when compared to Lynch and Webb, 1973a (glucose: 91.1 ± 6.3, 166.8 ± 25.5, 33.4 ± 10.6 mg/dL).4 The current study's market crab glucose value most closely resembles those of the published August crab data (Lynch and Webb, 1973a). Perhaps crabs are consuming less food in late summer, resulting in a lower hemolymph glucose, which would be consistent with dry-stored, market purchased crabs in January.
While this may be the first study to document hemolymph biochemical values for retail market C. sapidus, a number of published accounts measure and report hemolymph parameters for other species of decapod crustaceans exposed to air, including the effects of commercial handling.5-8 Biochemical hemolymph values for captive and market blue crabs, as well as related crustaceans, edible mollusks, and other commercially available invertebrates, could be useful for health assessments and issues related to animal welfare.
Acknowledgements
The NCSU-CVM Dr. Robert J. Koller Aquatic Medicine Endowment provided financial support for this project.
References
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