RP16 Biomonitoring
Thursday, 17 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(CUR-1117-769666) Evaluation of the Asiatic Clam (Corbicula fluminea) as a Standard Toxicity Test Organism.

Currie, R¹, Baxter, R¹, Alexander, A², Echols, B², Cherry, D², ¹ Roanoke College, Salem, VA, USA² VA Tech, Blacksburg, VA, USA

ABSTRACT- Acute and chronic toxicity tests rely upon commonly accepted organisms such as Ceriodaphnia dubia, Daphnia magna and Pimephales promelas, to indicate various levels of pollution and to set protective limits for industrial discharges. These species are easily cultured and widely researched relative to toxicological responses which have resulted in well-established toxicity databases. However, due to the lentic nature of both C. dubia and D. magna and the wide distribution of P. promelas, these organisms may not be protective of more lotic, sedimentary organisms such as freshwater mussels. The goal of this research was to provide an additional test organism, Corbicula fluminea, for use in standard toxicity tests. Corbicula has the potential to be utilized in both acute and chronic water column tests and chronic sediment tests. The first objective of this research focused on the laboratory culturing of recently released pediveligers in an effort to effectively maintain pediveliger populations through maturity into umbonal juveniles. Attempts to culture pediveligers through the juvenile stage were unsuccessful. A secondary objective was to use developing juveniles to establish LC₅₀ values for comparison to currently used test organisms. Acute toxicity test results showed C. fluminea (≤24 hrs) to be more sensitive to sodium chloride (NaCl) than C. dubia or D. magna with a mean LC₅₀ value of 1.41 g/L NaCl in 48-hr toxicity tests compared to 2.26 g/L (C. dubia) and 4.56 g/L (D. magna). Corbicula were even more sensitive to NaCl after 7-days old with a mean LC₅₀ value of 0.96 g/L.

Key words: Corbicula culturing, Bioassays, pediveligers, NaCl sensitivity