HR: 09:30h
AN: NB41D-05 INVITED     [Abstracts]
TI: Validating the Assumption of Annual Shell Ring Deposition in Freshwater Mussels
AU: * Commens, A M
EM: acommens@fs.fed.us
AF: USDA Forest Service, Center for Bottomland Hardwoods Research, 1000 Front Street, Oxford, MS 38655 United States
AU: Haag, W R
EM: whaag@fs.fed.us
AF: USDA Forest Service, Center for Bottomland Hardwoods Research, 1000 Front Street, Oxford, MS 38655 United States
AB: We evaluated the assumption of annual shell ring deposition by freshwater mussels in three rivers (Little Tallahatchie, Mississippi, 2000 and 2003; Sipsey, Alabama, 2000; St. Frances, Arkansas, 2003) using 14 species (Amblema plicata, Elliptio arca, Fusconaia cerina, F. flava, Lampsilis cardium, L. teres, Leptodea fragilis, Obliquaria reflexa, Potamilus purpuratus, Quadrula asperata, Q. pustulosa, Q. quadrula, Q, rumphiana, Tritogonia verrucosa). In 2000 we filed a notch in the shell margin, returned animals to the water, and retrieved them one year later. In 2003 we measured shell length and affixed numbered tags, returned animals to the water, and retrieved them one year later. After retrieval, we examined external and internal shell rings using thin-sections. For both methods, all species at all sites grew and deposited a single winter rest line between times of initial and final collection. Handling produced a conspicuous disturbance ring in all species. Characteristics of annual rings, disturbance rings, and false annuli differed qualitatively. Growth of some individuals was reduced after handling but negative growth occurred only in a few large individuals. Annual shell ring formation occurs consistently across species, space, and time. Formation of disturbance rings associated with collection indicates that mussels are extremely sensitive to handling.
DE: 9810 New fields (not classifiable under other headings)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly