DAO 65:159-165 (2005)  -  doi:10.3354/dao065159

Evaluation of a nonlethal technique for hemolymph collection in Elliptio complanata, a freshwater bivalve (Mollusca: Unionidae)

Lori L. Gustafson1,2,3,8, Michael K. Stoskopf1,3,5, Arthur E. Bogan1,4,William Showers1,6, Thomas J. Kwak1,7, Shane Hanlon2,9, Jay F. Levine1,2,*

1Environmental Medicine Consortium, 2Population Health and Pathobiology and 3Department of Clinical Sciences;College of Veterinary Medicine, North Carolina State University, Box 8401, Raleigh, North Carolina 27606, USA
4North Carolina State Museum of Natural Sciences, 11 West Jones St., Raleigh, North Carolina 27601-1029, USA
5Department of Environmental and Molecular Toxicology, Box 7633, College of Agriculture and Life Sciences,
6Department of Marine, Earth and Atmospheric Sciences, Box 8208, College of Physical and Mathematical Sciences, and
7US Geological Survey, North Carolina Cooperative Fish and Wildlife Research Unit, Box 7617,Department of Zoology; North Carolina State University, Raleigh, North Carolina 27695, USA
8Present address: USDA Animal and Plant Health Inspection Service, 16 Deep Cove Rd, Eastport, Maine 04631, USA
9Present address: US Fish and Wildlife Services, Southwestern Virginia Field Office, 330 Cummings St., Abingdon, Virginia 24210, USA
*Corresponding author. Email:

ABSTRACT: Hemolymph, the circulatory fluid of bivalves, transports nutrients, respiratory gases, enzymes, metabolic wastes, and toxicants throughout the body. Hemolymph can provide information pertinent to health assessment of animals or populations, but is not commonly used in freshwater bivalves partly because of the lack of tested, practical techniques for its nonlethal collection. The objective of this study was to evaluate the effect of hemolymph collection on the growth and survival of Elliptio complanata, a freshwater bivalve (Unionidae). We describe a simple technique for the collection of hemolymph from the anterior adductor muscle sinus of E. complanata. To evaluate the effect of hemolymph sampling on mussel survival and growth, 30 mussels sampled using the technique and 30 unsampled controls were followed for 3 mo post collection. Nine animals were sampled 3 times over 7 mo to monitor effects of repeated sampling. No negative impacts on survival or growth were observed in either the singly or repeatedly sampled animals. We also compared the composition of hemolymph collected from the adductor muscle sinus with that collected from the ventricle of the heart. Calcium levels and cell count of hemolymph obtained from the adductor sinus and ventricle were significantly different. There was no significant difference between collection sites for magnesium, phosphorus, ammonia, protein, sodium, potassium, or chloride. We conclude that collection of hemolymph from the adductor sinus is safe for sampled E. complanata and should be explored as a relatively non-invasive, and potentially useful, approach to the evaluation of freshwater mussel health.

KEY WORDS: Unionidae · Freshwater mussels · Hemolymph · Nonlethal sampling

Full text in pdf format